Siloxane derivatives of 2,2,6,6-tetramethylpiperidine compounds as stabilizers

ABSTRACT

Novel polymethylpiperidine compounds of general formula (I) containing silane groups and effective as light stabilizers, heat stabilizers and oxidation stabilizers for organic materials. 
     The meanings of R 1 , R 2 , R 3 , R 4  and n are defined in the text. ##STR1##

This application is a continuation of Ser. No. 08/207,532, filed on Mar. 7, 1994 now abandoned.

The present invention relates to novel polymethylpiperidine compounds containing silane groups, their use as light stabilisers, heat stabilisers and oxidation stabilisers for organic materials, particularly synthetic polymers, and organic materials thus stabilised.

The stabilisation of synthetic polymers with derivatives of 2,2,6,6-tetramethylpiperidine containing silane groups has been described in various patents, in particular in U.S. Pat. Nos. 4,177,186, 4,859,759, 4,895,885, 4,946,880 and 4,948,888, in European Patents 162 524, 244 026, 343 717, 388 321, 461 071 and 491 659 and in DD Patents 234 682 and 234,683.

The present invention relates to novel compounds of general formula (I) ##STR2## in which R₁ is hydrogen, C₁ -C₈ alkyl, O·, OH, CH₂ CN, C₁ -C₁₈ alkoxy, C₅ -C₁₂ cycloalkoxy, C₃ -C₆ alkenyl, C₇ -C₉ phenylalkyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl, or aliphatic C₁ -C₈ acyl;

R₂ and R₃, which may be identical or different, are C₁ -C₈ alkyl, phenyl, C₁ -C₈ alkoxy or a group of formula (II) ##STR3## n is 1,2,3 or 4; if n is 1, R₄ is C₂ -C₃₀ alkyl, C₅ -C₁₂ cycloalkyl which is unsubstituted or substituted with 1, 2 or 3 C₁ -C₄ alkyl or one of the groups of formulae (IIIa)-(IIId) ##STR4## in which R₅ is C₁ -C₁₈ alkyl, C₃ -C₃₀ alkyl interrupted by one or more oxygen atoms, C₅ -C₁₂ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, phenyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl or with C₁ -C₄ alkoxy, C₇ -C₉ phenylalkyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl, a group of formula (IV) ##STR5## where R₁₄ has any one of the meanings given for R₁, or R₅ is aliphatic, cycloaliphatic or aromatic acyl containing not more than 22 carbon atoms or a group ##STR6## where R₁₅ and R₁₆, which may be identical or different, are hydrogen, C₁ -C₁₈ alkyl, C₅ -C₁₂ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, C₇ -C₉ phenylalkyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl or a group of formula (IV), or ##STR7## is a heterocyclic group with 5-7 members, or one of the groups of formulae (Va)-(Vc) ##STR8## in which R₁₄ is as defined above, X₂ is --CH₂ CH₂ --, --CO--, --COCO-- or --COCH₂ CO-- and q is zero or 1; R₆ is C₂ -C₁₈ alkylene; R₇ and R₈, which may be identical or different, are as defined above for R₁₅ and R₁₆, or R₇ is also (C₁ -C₁₈ alkoxy)carbonyl or aliphatic, cycloaliphatic or aromatic acyl containing not more than 22 carbon atoms, or ##STR9## is a heterocyclic group having 5-7 members or one of the groups of formulae (Va)-(Vc) or one of the groups of formulae (VIa)-(VIc) ##STR10## in which X₃ is --O-- or ##STR11## where R₂₀ is as defined above for R₁₅ and R₁₆ ; R₁₇ is as defined above for R₇ or R₁₇ --X₃ -- is hydrogen or a nitrogen-containing heterocyclic group having 5-7 members, with the free valency on the nitrogen atom, or the group ##STR12## group, R₁₄ is as defined above, R₁₈ is hydrogen, methyl, acetyl or benzyl and R₁₉ is hydrogen or C₁ -C₃₀ alkyl; R₉ is C₃ -C₁₈ alkylene; R₁₀ is C₁ -C₁₈ alkyl, C₅ -C₁₂ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, C₇ -C₉ phenylalkyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl or a group of formula (IV), or R₁₀ is a group of formula (VII) ##STR13## with R₁, R₂, R₃ and R₆ as defined above; X₁ is as defined above for X₃ or R₁₀ X₁ -- is a nitrogen-containing heterocyclic group having 5-7 members, with the free valency on the nitrogen atom, or one of the groups of formulae (Va)-(Vc) or (VIa)-(VIc); p is 1,2 or 3 and, if p is 1, R₁₁ is C₂ -C₁₈ alkylene, if p is 2, R₁₁ is C₂ -C₂₀ alkanetriyl, C₅ -C₇ cycloalkanetriyl or C₇ -C₉ bicycloalkanetriyl and, if p is 3, R₁₁ is C₃ -C₆ alkanetetrayl; R₁₂ is as defined above for R₁₅ and R₁₆ and R₁₃ is a direct bond or C₁ -C₃₀ alkylene; if n is 2, R₄ is C₂ -C₁₂ alkylene, C₄ -C₂₂ alkylene interrupted by an oxygen atom or by an ##STR14## group, where R₂₁ is as defined above for R₇, or R₄ is one of the groups of formulae (VIIIa)-(VIIIc) ##STR15## in which X₄ and X₅, which may be identical or different, are --O-- or ##STR16## where R₂₈ is as defined above for R₇ ; R₂₂ is C₂ -C₁₈ alkylene or a --C_(r) H_(2r) CO-- group, where r is an integer from 2 to 18 and the carbonyl group is bonded to X₄ or X₅ ; R₂₃ is C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms, C₅ -C₇ cycloalkylene, C₅ -C₇ cycloalkylenedi(C₁ -C₄ alkylene), C₁ -C₄ alkylenedi(C₅ C₇ cycloalkylene), isopropylidene-dicyclohexylene, phenylene which is unsubstituted or substituted by 1 or 2 C₁ -C₄ alkyl, phenylenedi(C₁ -C₄ alkylene), C₂ -C₄ alkylidenediphenylene or a group of formula (IXa) or (IXb) ##STR17## in which R₂₉ is hydrogen or C₁ -C₄ alkyl and R₃₀ is C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms or phenylenedi(C₁ -C₄ alkylene) or, if R₂₂ is C₂ -C₁₈ alkylene, R₂₃ is also carbonyl, a ##STR18## group, where R₃₁ is a direct bond, C₁ -C₁₂ alkylene, C₂ -C₂₀ alkylidene, C₅ -C₇ cycloalkylene or phenylene which is unsubstituted or substituted with 1 or 2 C₁ -C₄ alkyl, R₃₂ and R₃₄ are C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms, C₅ -C₇ cycloalkylene, C₅ -C₇ cycloalkylenedi(C₅ -C₄ alkylene), C₁ -C₄ alkylenedi(C₅ -C₇ cycloalkylene), C₂ -C₄ alkylenedi(C₅ -C₇ cycloalkylene) or a group of formula (IXa) or (IXb), and R₃₃ and R₃₅, which may be identical or different, are as defined above for R₁₅ and R₁₆, or the --R₂₃ --X₅ -- group is a ##STR19## group or the --X₄ --R₂₃ --X₅ -- group is a ##STR20## group with X₂ as defined above or a ##STR21## group; R₂₄ is C₃ -C₁₈ alkylene; X₆ and X₇, which may be identical or different, are as defined above for X₄ and X₅ ; R₂₅ is C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms, C₅ -C₇ cycloalkylene, C₅ -C₇ cycloalkylenedi(C₁ C₄ alkylene), C₁ -C₄ alkylenedi(C₅ -C₇ cycloalkylene), carbonyl, or ##STR22## group, with R₃₁ and R₃₂ as defined above, or the --X₆ --R₂₅ --X₇ -- group is an ##STR23## group, where R₃₆ is as defined above for R₇ and X₂ is as defined above, or the ##STR24## group is a ##STR25## group; R₂₆ is C₃ -C₁₈ alkylene or a group of formula (X) ##STR26## where R₃₇ is C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms, C₅ -C₇ cycloalkylene, C₅ -C₇ cycloalkylenedi(C₁ -C₄ alkylene) or C₁ -C₄ alkylenedi(C₅ -C₇ cycloalkylene) and R₂₇ is a direct bond or C₁ -C₃₀ alkylene; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe) ##STR27## in which R₃₈ is C₃ -C₁₂ alkanetriyl or aliphatic or aromatic triacyl containing not more than 12 carbon atoms; R₃₉ is C₂ -C₁₈ alkylene or, if R₃₈ is C₃ -C₁₂ alkanetriyl, R₃₉ is also a --C_(s) H_(2s) CO-- group where s is an integer from 2 to 18 and the carbonyl group is bonded to the oxygen atom; R₄₀, R₄₁ and R₄₂, which may be identical or different, are C₃ -C₁₈ alkylene or R₄₀ is also a ##STR28## group, where the carbonyl group is bonded to the nitrogen atom and R₄₅ is C₂ -C₁₈ alkylene; R₄₃ is C₃ -C₁₈ alkylene and R₄₄ is C₂ -C₆ alkylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc) ##STR29## in which R₄₆ is C₄ -C₆ alkanetetrayl or aliphatic or aromatic tetraacyl containing not more than 12 carbon atoms; R₄₇ is C₂ -C₁₈ alkylene or, if R₄₆ is C₄ -C₁₂ alkanetetrayl, R₄₇ is also a --C_(s) H_(2s) CO-- group as defined above; R₄₈ is C₃ -C₁₈ alkylene and R₄₉ is as defined above for R₂₅.

Examples of alkyl containing not more than 30 carbon atoms are methyl, ethyl, propyl, isopropyl, butyl, 2-butyl, isobutyl, t-butyl, pentyl, 2-pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, t-octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl, hexacosyl, octacosyl and triacontyl.

R₄ is preferably C₄ -C₂₈, in particular C₁₂ -C₁₈ alkyl. Preferred examples of C₃ -C₃₀ alkyl interrupted by one or more oxygen atoms are the groups R_(a) --(OCH₂ CH₂)_(x) --, in which R_(a) is C₁ -C₁₈ alkyl and x is an integer from 1 to 6.

Examples of alkoxy containing not more than 18 carbon atoms are methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, decyloxy, dodecyloxy, tetradecyloxy, hexadecyloxy and octadecyloxy. For R₁ and R₁₄, C₆ -C₁₂ alkoxy, in particular heptoxy or octoxy, is preferred.

Examples of C₅ -C₁₂ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl are cyclopentyl, methylcyclopentyl, dimethylcyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, trimethylcyclohexyl, t-butylcyclohexyl, cyclooctyl, cyclodecyl and cyclododecyl. Unsubstituted or substituted cyclohexyl is preferred.

For R₁ and R₁₄, examples of C₅ -C₁₂ cycloalkoxy are cyclopentoxy, cyclohexoxy, cycloheptoxy, cyclooctoxy, cyclodecyloxy and cyclododecyloxy. Cyclopentoxy and cyclohexoxy are preferred.

For R_(l) and R₁₄, examples of C₃ -C₆ alkenyl are allyl, 2-methylallyl, butenyl and hexenyl. Allyl is particularly preferred.

Representative examples of phenyl which is substituted with 1,2 or 3 C₁ -C₄ alkyl or with C₁ -C₄ alkoxy are methylphenyl, dimethylphenyl, trimethylphenyl, t-butylphenyl, di-t-butylphenyl, 3,5-di-t-butyl-4-methylphenyl, methoxyphenyl, ethoxyphenyl and butoxyphenyl.

Examples of C₇ -C₉ phenylalkyl which is unsubstituted or substituted on the phenyl with 1, 2 or 3 C₁ -C₄ alkyl are benzyl, methylbenzyl, dimethylbenzyl, trimethylbenzyl, t-butylbenzyl and 2-phenylethyl. Benzyl is preferred.

Representative examples of aliphatic, cycloaliphatic or aromatic acyl, containing not more than 22 carbon atoms, are acetyl, propionyl, butyryl, isobutyryl, pentanoyl, hexanoyl, heptanoyl, octanoyl, 2-ethylhexanoyl, decanoyl, undecanoyl, dodecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, eicosanoyl, docosanoyl, acryloyl, crotonyl, cyclohexanecarbonyl, benzoyl, t-butylbenzoyl, 3,5-di-t-butyl-4-hydroxybenzoyl and 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl.

Preferred examples of the nitrogen-containing heterocyclic groups with 5-7 members and with the free valency on the nitrogen atom are 1-pyrrolidyl, 1-piperidyl, 4-morpholinyl, 4-methyl-1-piperazinyl and 1-hexahydroazepinyl. 4-Morpholinyl is particularly preferred.

Examples of alkylene containing not more than 30 carbon atoms are methylene, ethylene, propylene, trimethylene, 2-methyltrimethylene, tetramethylene, pentylene, hexylene, heptylene, octylene, decylene, undecylene, dodecylene, tetradecylene, hexadecylene, heptadecylene, octadecylene, eicosylene, docosylene, tetracosylene, hexacosylene, octacosylene and triacontylene.

Representative examples of C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms are 3-oxapentane-1,5-diyl, 4-oxaheptane-1,7-diyl, 3,6-dioxaoctane-1,8-diyl, 4,7-dioxadecane-1,10-diyl, 4,9-dioxadodecane-1,12-diyl, 3,6,9-trioxaundecane-1,11-diyl and 4,7,10-trioxatridecane-1,13-diyl.

Where R₄ is C₄ -C₂₂ alkylene interrupted by an oxygen atom, representative examples are 3-oxapentane-1,5-diyl, 3-oxahexane-1,6-diyl, 4-oxaheptane-1,7-diyl, 2,6-dimethyl-4-oxaheptane-1,7-diyl, 4-oxapentadecane-1,15-diyl or a --(CH₂)₃ --O--R_(b) -- group, where R_(b) is octadecylene.

Where R₄ is C₄ -C₂₂ alkylene interrupted by an ##STR30## group, preferred examples are the groups: ##STR31## where R₂₁ and R_(b) are as defined above.

Preferred examples of C₂ -C₂₀ alkylidene are ethylidene, propylidene, butylidene, pentylidene, heptylidene, nonylidene, undecylidene, tridecylidene, pentadecylidene, heptadecylidene and nonadecylidene.

Representative examples of groups containing 1 or 2 C₅ -C₇ cycloalkylene groups are cyclohexylene, methylcyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene and isopropylidenedicyclohexylene.

Representative examples of groups containing 1 or 2 phenylene groups are phenylene, methylphenylene, dimethylphenylene, di-t-butylphenylene, phenylenedimethylene and isopropylidenediphenylene.

If R₁₁ is C₂ -C₂₀ alkanetriyl, representative examples are ethanetriyl, propanetriyl, butanetriyl or a ##STR32## group, where R_(c) is C₃ -C₁₈ alkylene.

If R₃₈ is C₃ -C₁₂ alkanetriyl, preferred examples are 1,2,3-propanetriyl, 1,2,4-butanetriyl, 1,2,6-hexanetriyl or the ##STR33## group, where R_(d) is methyl or ethyl.

If R₁₁ is C₅ -C₇ cycloalkanetriyl or C₇ -C₉ bicycloalkanetriyl, representative examples are the ##STR34## groups.

R₃₈ as aliphatic or aromatic triacyl containing not more than 12 carbon atoms is, for example, a triacyl derived from methanetricarboxylic, 1,1,2-ethanetricarboxylic, 1,2,3-propanetricarboxylic, citric, 1,2,3-butanetricarboxylic, 1,2,4-benzenetricarboxylic or 1,3,5-benzenetricarboxylic acids.

If R₁₁ is C₃ -C₆ alkanetetrayl, representative examples are propanetetrayl, butanetetrayl and pentanetetrayl.

If R₄₆ is C₄ -C₆ alkanetetrayl, preferred examples are 1,2,3,4-butanetetrayl and the ##STR35##

R₄₆, as aliphatic or aromatic tetraacyl containing not more than 12 carbon atoms is, for example, a tetraacyl derived from 1,1,3,3-propanetetracarboxylic, 1,2,3,4-butanetetracarboxylic or 1,2,4,5-benzenetetracarboxylic acids.

Preferred meanings of R₁ and R₁₄ are hydrogen, C₁ -C₄ alkyl, OH, C₆ -C₁₂ alkoxy, C₅ -C₈ cycloalkoxy, allyl, benzyl or acetyl, in particular hydrogen or methyl.

Preferred compounds of formula (I) are those in which R₂ and R₃, which may be identical or different, are C₁ -C₄ alkyl, C₁ -C₄ alkoxy or a group of formula (II), n is 1,2,3 or 4 and, if n is 1, R₄ is C₄ -C₂₈ alkyl, C₅ -C₈ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, or one of the groups of the formulae (IIIa)-(IIId) in which R₅ is C₄ -C₁₈ alkyl, C₄ -C₂₈ alkyl interrupted by one or more oxygen atoms, C₅ -C₈ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, phenyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl or with C₁ -C₄ alkoxy, benzyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl, a group of formula (IV), aliphatic, cycloaliphatic or aromatic acyl containing not more than 20 carbon atoms or an ##STR36## group, where R₁₅ and R₁₆, which may be identical or different, are hydrogen, C₁ -C₁₈ alkyl, C₅ -C₈ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl or a group of formula (IV), or ##STR37## is 4-morpholinyl or one of the groups of formulae (Va)-(Vc), in which X₂ is --CH₂ CH₂ -- or --CO-- or --COCO-- and q is zero or 1; R₆ is C₂ -C₁₈ alkylene; R₇ and R₈, which may be identical or different, are as defined above for R₁₅ and R₁₆, or R₇ is also (C₂ -C₁₈ alkoxy)carbonyl or aliphatic, cycloaliphatic or aromatic acyl containing not more than 20 carbon atoms, or ##STR38## is 4-morpholinyl or one of the groups of formulae (Va)-(Vc) or one of the groups of formulae (VIa)-(VIc) in which X₃ is --O-- or ##STR39## where R₂₀ is as defined above for R₁₅ and R₁₆ ; R₁₇ is as defined above for R₇ or R₁₇ X₃ -- is hydrogen or 4-morpholinyl, R₁₈ is hydrogen or methyl and R₁₉ is hydrogen or C₃ -C₂₈ alkyl; R₉ is C₃ -C₁₈ alkylene; R₁₀ is C₂ -C₁₈ alkyl, C₅ -C₈ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl, a group of formula (IV) or a group of formula (VII), X₁ is as defined above for X₃ or R₁₀ X₁ -- is 4-morpholinyl or one of the groups of formulae (Va)-(Vc) or (VIa)-(VIc); p is 1,2 or 3 and, if p is 1, R₁₁ is C₂ -C.sub. 17 alkylene and, if p is 2, R₁₁ is C₂ -C₂₀ alkanetriyl or C₆ -C₇ cycloalkanetriyl and, if p is 3, R₁₁ is propanetriyl; R₁₂ is as defined above for R₁₅ and R₁₆ and R₁₃ is a direct bond or C₃ -C₂₈ alkylene; if n is 2, R₄ is C₂ -C₈ alkylene or C₄ -C₂₁ alkylene interrupted by an oxygen atom or by an ##STR40## group where R₂₁ is as defined above for R₇, or R₄ is one of the groups of formulae (VIIIa)-(VIIIc), in which X₄ and X₅, which may be identical or different, are --O-- or ##STR41## where R₂₈ is as defined above for R₇ ; R₂₂ is C₂ -C₁₈ alkylene or a C_(r) H_(2r) CO-- group, where r is an integer from 2 to 17 and the carbonyl group is bonded to X₄ or X₅, R₂₃ is C₂ -C₁₀ alkylene or C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, isopropylidenedicyclohexylene, phenylene, phenylenedimethylene, isopropylidenediphenylene or a group of formula (IXa) or (IXb) in which R₂₉ is hydrogen or methyl and R₃₀ is C₂ -C₁₀ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms or phenylenedimethylene or, if R₂₂ is C₂ -C₁₈ alkylene, R₂₃ is also carbonyl or a ##STR42## group, where R₃₁ is C₁ -C₁₀ alkylene, C₃ -C₁₉ alkylidene, cyclohexylene or phenylene, R₃₂ and R₃₄ are C₂ -C₁₀ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, isopropylidenedicyclohexylene or a group of formula (IXa) or (IXb) and R₃₃ and R₃₅, which may be identical or different, are as defined above for R₁₅ and R₁₆ or the --R₂₃ --X₅ group is a ##STR43## group or the --X₄ --R₂₃ --X₅ -- group is a 1,4-piperazinediyl group or a ##STR44## group; R₂₄ is C₃ -C₁₈ alkylene; X₆ and X₇, which may be identical or different, are as defined above for X₄ and X₅, R₂₅ is C₂ -C₁₀ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, carbonyl or a ##STR45## group, with R₃₁ and R₃₂ as defined above, or the --X₆ --R₂₅ --X₇ -- group is an ##STR46## group, where R₃₆ is as defined above for R₇ ; R₂₆ is C₃ -C₁₈ alkylene or a group of formula (X), where R₃₇ is C₂ -C₁₀ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene or methylenedicyclohexylene and R₂₇ is a direct bond or C₃ -C₂₈ alkylene; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe), in which R₃₈ is C₃ -C₁₀ alkanetriyl or aliphatic or aromatic triacyl containing not more than 10 carbon atoms; R₃₉ is C₂ -C₁₈ alkylene or, if R₃₈ is C₃ -C₁₀ alkanetriyl, R₃₉ is also a --C_(s) H_(2s) CO-- group, where s is an integer from 2 to 17 and the carbonyl group is bonded to the oxygen atom; R₄₀, R₄₁ and R₄₂, which may be identical or different, are C₃ - C₁₈ alkylene or R₄₀ is also a ##STR47## group, where the carbonyl group is bonded to the nitrogen atom and R₄₅ is C₂ -C₁₈ alkylene; R₄₃ is C₃ -C₁₁ alkylene and R₄₄ is C₂ -C₅ alkylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc) in which R₄₆ is C₄ -C₆ alkanetetrayl or aliphatic or aromatic tetraacyl containing not more than 10 carbon atoms, R₄₇ is C₂ C₁₈ alkylene or, if R₄₆ is C₄ -C₆ alkanetetrayl, R₄₇ is also a --C_(s) H_(2s) CO-- group as defined above; R₄₈ is C₃ -C₁₁ alkylene and R₄₉ is as defined above for R₂₅.

Particularly preferred compounds of formula (I) are those in which R₂ and R₃, which may be identical or different, are methyl, ethyl, methoxy, ethoxy or a group of formula (II), n is 1, 2, 3 or 4 and, if n is 1, R₄ is C₆ -C₂₄ alkyl, cyclohexyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl or one of the groups of formulae (IIIa)-(IIId), in which R₅ is C₆ -C₁₈ alkyl, C₆ -C₂₄ alkyl interrupted by one or more oxygen atoms, cyclohexyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl, a group of formula (IV), aliphatic, cycloaliphatic or aromatic acyl containing not more than 18 carbon atoms or an ##STR48## group, where R₁₅ and R₁₆, which may be identical or different, are C₁ -C₁₈ alkyl, cyclohexyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl or a group of formula (IV) or ##STR49## is one of the groups of formulae (Va)-(Vc), in which X₂ is --CH₂ CH₂ -- or --CO-- or --COCO-- and q is zero or 1; R₆ is C₂ -C₁₁ alkylene; R₇ and R₈, which may be identical or different, are as defined above for R₁₅ and R₁₆ or hydrogen or R₇ is also (C₄ -C₁₈ alkoxy)carbonyl or aliphatic, cycloaliphatic aromatic acyl containing not more than 18 carbon atoms, or ##STR50## is one of the groups of formulae (Va)-(Vc) or one of the groups of formulae (VIa)-(VIc), in which X₃ is --O-- or ##STR51## where R₂₀ is as defined above for R₁₅ and R₁₆ ; R₁₇ is as defined above for R₇ or R₁₇ X₃ -- is hydrogen, R₁₈ is hydrogen or methyl and R₁₉ is hydrogen or C₃ -C₂₄ alkyl; R₉ is C₃ -C₁₁ alkylene; R₁₀ is C₄ -C₁₈ alkyl, cyclohexyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl, a group of formula (IV) or a group of formula (VII), X₁ is as defined above for X₃ or R₁₀ X₁ -- is one of the groups of formulae (Va)-(Vc) or (VIa)-(VIc); p is 1 or 2 and, if p is 1, R₁₁ is C₂ -C₁₇ alkylene and, if p is 2, R₁₁ is C₂ -C₁₆ alkanetriyl; R₁₂ is as defined above for R₁₅ and R₁₆ and R.sub. 13 is a direct bond or C₃ -C₂₄ alkylene; if n is 2, R₄ is C₂ -C₆ alkylene or C₄ -C₁₄ alkylene interrupted by an oxygen atom or by an ##STR52## group, where R₂₁ is as defined above for R₇ or R₄ is one of the groups of formulae (VIIIa)-(VIIIc) in which X₄ and X₅, which may be identical or different, are --O-- or ##STR53## where R₂₈ is as defined above for R₇ ; R₂₂ is C₂ -C₁₁ alkylene or a --C_(r) H_(2r) CO-- group, where r is an integer from 2 to 10 and the carbonyl group is bonded to X₄ or X₅, R₂₃ is C₂ -C₈ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, phenylene, phenylenedimethylene or a group of formula (IXa), in which R₂₉ is hydrogen or methyl or, if R₂₂ is C₂ -C₁₁ alkylene, R₂₃ is also carbonyl, or a ##STR54## group, where R₃₁ is C₂ -C₈ alkylene, C₅ -C₁₃ alkylidene, cyclohexylene or phenylene, R₃₂ and R₃₄ are C₂ -C₈ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene or a group of formula (IXa) and R₃₃ and R₃₅, which may be identical or different, are as defined above for R₁₅ and R₁₆ or the --R₂₃ --X₅ -- group is a ##STR55## group; R₂₄ is C₃ -C₁₁ alkylene; X₆ and X₇, which may be identical or different, are as defined above for X₄ and X₅, R₂₅ is C₂ -C₈ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, carbonyl or a ##STR56## group, with R₃₁ and R₃₂ as defined above, or the group --X₆ --R₂₅ --X₇ is an ##STR57## group, where R₃₆ is as defined above for R₇, R₂₆ is C₃ -C₁₁ alkylene or a group of formula (X), where R₃₇ is C₂ -C₈ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene or methylenedicyclohexylene and R₂₇ is a direct bond or C₃ -C₂₄ alkylene; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe), in which R₃₈ is C₃ -C₈ alkanetriyl or aliphatic C₄ -C₇ triacyl; R₃₉ is C₂ -C₁₁ alkylene or, if R₃₈ is C₃ -C₈ alkanetriyl, R₃₉ is also a --C_(s) H_(2s) CO-- group, where s is an integer from 2 to 10 and the carbonyl group is bonded to the oxygen atom, R₄₀, R₄₁ and R₄₂, which may be identical or different, are

C₃ -C₁₁ alkylene or R₄₀ is also a ##STR58## group, where the carbonyl group is bonded to the nitrogen atom and R₄₅ is C₂ -C₁₁ alkylene, R₄₃ is C₃ -C₆ alkylene and R₄₄ is C₂ -C₄ alkylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc) in which R₄₆ is C₄ -C₅ alkanetetrayl or aliphatic C₆ -C₈ tetraacyl, R₄₇ is C₂ -C₁₁ alkylene or, if R₄₆ is C₄ -C₅ alkanetetrayl, R₄₇ is also a --C_(s) H_(2s) CO-- group as defined above; R₄₈ is C₃ -C₆ alkylene and R₄₉ is as defined above for R₂₅.

Compounds of formula (I) of special interest are those in which R₂ and R₃, which may be identical or different, are methyl, methoxy, ethoxy or a group of formula (II), n is 1,2,3 or 4 and, if n is 1, R₄ is C₈ -C₂₀ alkyl, cyclohexyl or one of the groups of formulae (IIIa)-(IIId) in which R₅ is C₈ -C₁₈ alkyl, C₁₀ -C₂₂ alkyl interrupted by 1 or 2 oxygen atoms, cyclohexyl, benzyl, a group of formula (IV), aliphatic C₈ -C₁₈ acyl or an ##STR59## group, where R₁₅ and R₁₆, which may be identical or different, are C₄ -C₁₈ alkyl, cyclohexyl, benzyl or a group of formula (IV), or ##STR60## is one of the groups of formulae (Va)-(Vc), in which X₂ is --CH₂ CH₂ --, --CO-- or --COCO-- and q is zero or 1; R₆ is C₂ -C₅ alkylene; R₇ and R₈, which may be identical or different, are as defined above for R₁₅ and R₁₆ or are hydrogen, or R₇ is also (C₈ -C₁₈ alkoxy)carbonyl or aliphatic C₈ -C₁₈ acyl or ##STR61## is one of the groups of formulae (Va)-(Vc) or one of the groups of formulae (VIa)-(VIc), in which X₃ is --O-- or ##STR62## where R₂₀ is as defined above for R₁₅ and R₁₆ ; R₁₇ is as defined above for R₇, R₁₈ is hydrogen and R₁₉ is C₈ -C₁₈ alkyl; R₉ is C₃ -C₅ alkylene; R₁₀ is C₈ -C₁₈ alkyl, cyclohexyl, benzyl, a group of formula (IV) or a group of formula (VII), X₁ is as described above for X₃ or R₁₀ X₁ -- is one of the groups of formulae (Va)-(Vc) or (VIa)-(VIc); p is 1 or 2 and, if p is 1, R₁₁ is C₂ -C₁₀ alkylene and, if p is 2, R₁₁ is C₂ -C₁₄ alkanetriyl; R₁₂ is as defined above for R₁₅ and R₁₆ and R₁₃ is a direct bond or C₃ -C₁₈ alkylene; if n is 2, R₄ is C₂ -C₄ alkylene, C₄ - C₁₄ alkylene interrupted by an oxygen atom or C₆ -C₁₀ alkylene interrupted by an ##STR63## group, where R₂₁ is as defined above for R₇, or R₄ is one of the groups of formulae (VIIIa)-(VIIIc), in which X₄ and X₅, which may be identical or different, are --O-- or ##STR64## where R₂₈ is as defined above for R₇ ; R₂₂ is C₂ -C₅ alkylene or a --C_(r) H_(2r) CO-- group, where r is an integer from 2 to 10 and the carbonyl group is bonded to X₄ or X₅, R₂₃ is C₂ -C₆ alkylene, C₆ -C₁₀ alkylene interrupted by 2 or 3 oxygen atoms, cyclohexylenedimethylene, methylenedicyclohexylene or a group of formula (IXa), in which R₂₉ is hydrogen or, if R₂₂ is C₂ -C₅ alkylene, R₂₃ is also carbonyl ##STR65## group, where R₃₃ and R₃₅ are a group of formula (IV), or the --R₂₃ --X₅ group is a ##STR66## group; R₂₄ is C₃ -C₅ alkylene; X₆ and X₇ are as defined above for X₄ and X₅ ; R₂₅ is C₂ -C₆ alkylene, C₆ -C₁₀ alkylene interrupted by 2 or 3 oxygen atoms, cyclohexylenedimethylene, methylenedicyclohexylene or a ##STR67## group; R₂₆ is C₃ -C₅ alkylene or a group of formula (X), where R₃₇ is C₂ -C₁₀ alkylene, C₆ -C₁₀ alkylene interrupted by 2 or 3 oxygen atoms, cyclohexylenedimethylene or methylenedicyclohexylene and R₂₇ is a direct bond or C₃ -C₁₈ alkylene; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe), in which R₃₈ is C₃ -C₆ alkanetriyl or aliphatic C₅ -C₇ triacyl; R₃₉ is C₂ -C₅ alkylene or, if R₃₈ is C₃ -C₆ alkanetriyl, R₃₉ is also a --C_(s) H_(2s) CO-- group, where s is an integer from 2 to 10 and the carbonyl group is bonded to the oxygen atom; R₄₀, R₄₁ and R₄₂, which may be identical or different, are C₃ -C₅ alkylene, or R₄₀ is also a ##STR68## group, where the carbonyl group is bonded to the nitrogen atom and R₄₅ is C₂ -C₁₁ alkylene; R₄₃ is C₃ -C₅ alkylene and R₄₄ is C₂ -C₄ alkylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc), in which R₄₆ is a ##STR69## group, R₄₇ is C₂ -C₅ alkylene; R₄₈ is C₃ -C₅ alkylene and R₄₉ is as defined above for R₂₅.

Compounds of formula (I) of particular interest are those in which R₁ and R₁₄ are hydrogen or methyl, R₂ and R₃, which may be identical or different, are methyl or a group of formula (II), n is 1,2,3, or 4 and, if n is 1, R₄ is C₁₂ -C₁₈ alkyl or one of the groups of formulae (IIIa)-(IIId) in which R₅ is C₁₂ -C₁₈ alkyl, a group of formula (IV), aliphatic C₁₂ -C₁₈ acyl or an ##STR70## group, where R₁₅ and R₁₆, which may be identical or different, are C₄ -C₁₂ alkyl or a group of formula (IV), R₆ is ethylene or trimethylene, R₇ and R₈, which may be identical or different, are as defined above for R₁₅ or R₁₆ or hydrogen, or ##STR71## is a group of formula (Va), in which X₂ is --CH₂ CH₂ -- or --CO-- and q is zero or 1, or a group of formula (VIb) in which R₁₈ is hydrogen, R₉ is trimethylene, R₁₀ is a group of formula (IV), X₁ is --O-- or --NH--, p is 1 or 2 and, if p is 1, R₁₁ is C₂ -C₁₀ alkylene and, if p is 2, R₁₁ is C₂ -C₄ alkanetriyl, R₁₂ is C₁₂ -C₁₈ alkyl and R₁₃ is a direct bond; if n is 2, R₄ is a ##STR72## group, where R₂₁ is C₁₂ -C₁₈ alkyl, (C₁₂ -C₁₈ alkoxy)carbonyl or aliphatic C₁₂ -C₁₈ acyl, or R₄ is one of the groups of formulae (VIII)-(VIIIc), in which X₄ and X₅ are ##STR73## where R₂₈ is a group of formula (IV), R₂₂ is trimethylene or a --CH₂ CH₂ CO-- group, with the carbonyl group bonded to X₄ or X₅, R₂₃ is --(CH₂)₂₋₆ --, R₂₄ is trimethylene, X₆ and X₇ are --O-- , R₂₅ is ##STR74## R₂₆ is a group of formula (X), in which R₃₇ is --(CH₂)₂₋₆ -- and R₂₇ is a direct bond; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe), in which R₃₈ is a ##STR75## --CH₂ CH₂ CO-- group, with the carbonyl group bonded to the oxygen atom and R₄₀, R₄₁, R₄₂, R₄₃ and R₄₄ are trimethylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc), in which R₄₆ is a ##STR76## group, R₄₇ is C₂ -C₅ alkylene; R₄₈ is C₃ -C₅ alkylene and R₄₉ is as defined above for R₂₅.

The compounds of the present invention can be prepared in accordance with various processes known per se.

According to process A, the compounds of the formula (I) can be prepared by reacting, in the appropriate molar ratios and in the presence of a transesterification catalyst, a compound of formula (XIII) ##STR77## with a compound of formula (XIV) ##STR78## where n is as defined above, G is C₁ -C₈ alkoxy, R₂ ' and R₃ ', which may be identical or different, are C₁ -C ₈ alkyl, phenyl or C₁ -C₈ alkoxy and R₄ ' is as defined above for R₄, except that, when R₁₀ is a group of formula (VII), the said group is replaced by the group of formula (VII') ##STR79##

The reaction is carried out without a solvent or in an inert organic solvent, for example benzene, toluene, xylene, mesitylene, cyclohexane, heptane, octane, tetrahydrofuran or dioxane, at a temperature of between 65° and 200° C., preferably between 100° and 180° C.

As the transesterification catalyst there may for example be used an alkali metal, a C₁ -C₄ alkoxide or amide or hydride of an alkali metal, a C₁ -C₄ alkoxide of Ti(IV) or dibutyltin oxide.

If R₄ is a group of formula (IIIc), in which X₁ is --O-- and R₁₀ is different from a group of formula (IV), it is possible that, in the same reaction, the said group R₁₀ can also be replaced by a group of formula (IV).

According to process B, the compounds of formula (I) can be prepared by reacting, in the appropriate molar ratios and in the presence of an organic base, a compound of formula (XIII) with a compound of formula (XV) ##STR80## where n is as defined above, R₂ " and R₃ ", which may be identical or different, are C₁ -C₈ alkyl, phenyl or Cl and R₄ " is as defined above for R₄, except that, if R₁₀ is a group of formula (VII), the said group is replaced by the group of formula (VII") ##STR81##

The reaction is carded out in an inert organic solvent, for example one of the solvents mentioned above, at a temperature of between 0° and 150° C., preferably between 20° and 120° C.

As the organic base there may for example be employed methylamine or tributylamine or pyridine, in an amount at least equivalent to the hydrochloric acid liberated during the reaction.

An excess of the organic base can also be employed as the solvent. As an alternative to the said organic bases, it is possible to employ the compounds of formula (XIII) in the form of alcoholates of alkali metals, in particular of sodium or potassium.

According to process C, the compounds of formula (I) can be prepared by reacting, in the appropriate molar ratios and in the presence of a hydrosilylation catalyst, a compound of formula (XVI) ##STR82## with an alkene capable of forming the group R₄.

The reaction is carried out in an inert organic solvent, for example one of the solvents mentioned above, at a temperature of between 50° and 150° C., preferably between 80° and 130° C.

As a hydrosilylation catalyst there may be employed, for example, Pd, Pt, Rh or their derivatives, preferably complexes of Pt and Rh, in particular H₂ PtCl₆, the PtCl₂ (Ph--CH═CH₂)₂ complex and the PtCl₂ (dimethyl sulfoxide)₂ complex.

The reaction can be carried out without a solvent or in an inert organic solvent, for example one of the solvents mentioned above, at a temperature of between 50° and 150° C., preferably between 80° and 130° C.

The intermediate compounds of formula (XIV) and (XV), respectively, and can be prepared by hydrosilylation of an alkene capable of forming the group R₄, and with a silane of formula ##STR83## in the presence of a hydrosilylation catalyst, in accordance with process C.

The intermediate compounds of formula (XVI) can be prepared by reacting a compound of formula (XIII) with a silane of formula ##STR84## in the presence of a transesterification catalyst, in accordance with process A.

The compounds of formula (XIII) and the other intermediates are commercially available or can be prepared in accordance with known processes.

As pointed out initially, the compounds of formula (I) are very effective in improving the light resistance, heat resistance and oxidation resistance of organic materials, in particular synthetic polymers and copolymers.

Examples of such organic materials which can be stabilised are:

1. Polymers of monoolefins and diolefins, for example polypropylene, polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene, polyisoprene or polybutadiene, as well as polymers of cycloolefins, for instance of cyclopentene or norbornene, polyethylene (which optionally can be crosslinked), for example high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), branched low density polyethylene (BLDPE).

Polyolefins, i.e. the polymers of monoolefins exemplified in the preceding paragraph, preferably polyethylene and polypropylene, can be prepared by different, and especially by the following, methods:

a) radical polymerisation (normally under high pressure and at elevated temperature).

b) catalytic polymerisation using a catalyst that normally contains one or more than one metal of groups IVb, Vb, VIb or VIII of the Periodic Table. These metals usually have one or more than one ligand, typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls that may be either π- or σ-coordinated. These metal complexes may be in the free form or fixed on substrates, typically on activated magnesium chloride, titanium(III) chloride, alumina or silicon oxide. These catalysts may be soluble or insoluble in the polymerisation medium. The catalysts can be used by themselves in the polymerisation or further activators may be used, typically metal alkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metal alkyloxanes, said metals being elements of groups Ia, Ha and/or IIIa of the Periodic Table. The activators may be modified conveniently with further ester, ether, amine or silyl ether groups. These catalyst systems are usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta), TNZ (DuPont), metallocene or single site catalysts (SSC).

2. Mixtures of the polymers mentioned under 1 ), for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP/HDPE, PP/LDPE) and mixtures of different types of polyethylene (for example LDPE/HDPE).

3. Copolymers of monoolefins and diolefins with each other or with other vinyl monomers, for example ethylene/propylene copolymers, linear low density polyethylene (LLDPE) and mixtures thereof with low density polyethylene (LDPE), propylene/but-1-ene copolymers, propylene/isobutylene copolymers, ethylene/but-1-ene copolymers, ethylene/hexene copolymers, ethylene/methylpentene copolymers, ethylene/heptene copolymers, ethylene/octene copolymers, propylene/butadiene copolymers, isobutylene/isoprene copolymers, ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers and their copolymers with carbon monoxide or ethylene/acrylic acid copolymers and their salts (ionomers) as well as terpolymers of ethylene with propylene and a diene such as hexadiene, dicyclopentadiene or ethylidene-norbornene; and mixtures of such copolymers with one another and with polymers mentioned in 1) above, for example polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl acetate copolymers (EVA), LDPE/ethylene-acrylic acid copolymers (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random polyalkylene/carbon monoxide copolymers and mixtures thereof with other polymers, for example polyamides.

4. Hydrocarbon resins (for example C₅ -C₉) including hydrogenated modifications thereof (e.g. tackifiers) and mixtures of polyalkylenes and starch.

5. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).

6. Copolymers of styrene or α-methylstyrene with dienes or acrylic derivatives, for example styrene/butadiene, styrene/acrylonitrile, styrene/alkyl methacrylate, styrene/butadiene/alkyl acrylate, styrene/butadiene/alkyl methacrylate, styrene/maleic anhydride, styrene/acrylonitrile/methyl acrylate; mixtures of high impact strength of styrene copolymers and another polymer, for example a polyacrylate, a diene polymer or an ethylene/propylene/diene terpolymer, and block copolymers of styrene such as styrene/butadiene/styrene, styrene/isoprene/styrene, styrene/ethylene/butylene/styrene or styrene/ethylene/propylene/styrene.

7. Graft copolymers of styrene or α-methylstyrene, for example styrene on polybutadiene, styrene on polybutadiene-styrene or polybutadiene-acrylonitrile copolymers; styrene and acrylonitrile (or methacrylonitrile) on polybutadiene; styrene, acrylonitrile and methyl methacrylate on polybutadiene; styrene and maleic anhydride on polybutadiene; styrene, acrylonitrile and maleic anhydride or maleimide on polybutadiene; styrene and maleimide on polybutadiene; styrene and alkyl acrylates or methacrylates on polybutadiene; styrene and acrylonitrile on ethylene/propylene/diene terpolymers; styrene and acrylonitrile on polyalkyl acrylates or polyalkyl methacrylates, styrene and acrylonitrile on acrylate/butadiene copolymers, as well as mixtures thereof with the copolymers listed under 6), for example the copolymer mixtures known as ABS, MBS, ASA or AES polymers.

8. Halogen-containing polymers such as polychloroprene, chlorinated rubbers, chlorinated or sulfochlorinated polyethylene, copolymers of ethylene and chlorinated ethylene, epichlorohydrin homo- and copolymers, especially polymers of halogen-containing vinyl compounds, for example polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, as well as copolymers thereof such as vinyl chloride/vinylidene chloride, vinyl chloride/vinyl acetate or vinylidene chloride/vinyl acetate copolymers.

9. Polymers derived from α,β-unsaturated acids and derivatives thereof such as polyacrylates and polymethacrylates; polymethyl methacrylates, polyacrylamides and polyacrylonitriles, impact-modified with butyl acrylate.

10. Copolymers of the monomers mentioned under 9) with each other or with other unsaturated monomers, for example acrylonitrile/butadiene copolymers, acrylonitrile/alkyl acrylate copolymers, acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halide copolymers or acrylonitrile/alkyl methacrylate/butadiene terpolymers.

11. Polymers derived from unsaturated alcohols and amines or the acyl derivatives or acetals thereof, for example polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate, polyvinyl butyral, polyallyl phthalate or polyallyl melamine; as well as their copolymers with olefins mentioned in 1) above.

12. Homopolymers and copolymers of cyclic ethers such as polyalkylene glycols, polyethylene oxide, polypropylene oxide or copolymers thereof with bisglycidyl ethers.

13. Polyacetals such as polyoxymethylene and those polyoxymethylenes which contain ethylene oxide as a comonomer; polyacetals modified with thermoplastic polyurethanes, acrylates or MBS.

14. Polyphenylene oxides and sulfides, and mixtures of polyphenylene oxides with styrene polymers or polyamides.

15. Polyurethanes derived from hydroxyl-terminated polyethers, polyesters or polybutadienes on the one hand and aliphatic or aromatic polyisocyanates on the other, as well as precursors thereof.

16. Polyamides and copolyamides derived from diamines and dicarboxylic acids and/or from aminocarboxylic acids or the corresponding lactams, for example polyamide 4, polyamide 6, polyamide 6/6, 6/10, 6/9, 6/12, 4/6, 12/12, polyamide 11, polyamide 12, aromatic polyamides starting from m-xylene diamine and adipic acid; polyamides prepared from hexamethylenediamine and isophthalic or/and terephthalic acid and with or without an elastomer as modifier, for example poly-2,4,4,-trimethylhexamethylene terephthalamide or poly-m-phenylene isophthalamide; and also block copolymers of the aforementioned polyamides with polyolefins, olefin copolymers, ionomers or chemically bonded or grafted elastomers; or with polyethers, e.g. with polyethylene glycol, polypropylene glycol or polytetramethylene glycol; as well as polyamides or copolyamides modified with EPDM or ABS; and polyamides condensed during processing (RIM polyamide systems).

17. Polyureas, polyimides, polyamide-imides and polybenzimidazoles.

18. Polyesters derived from dicarboxylic acids and diols and/or from hydroxycarboxylic acids or the corresponding lactones, for example polyethylene terephthalate, polybutylene terephthalate, poly-1,4-dimethylolcyclohexane terephthalate and polyhydroxybenzoates, as well as block copolyether esters derived from hydroxyl-terminated polyethers; and also polyesters modified with polycarbonates or MBS.

19. Polycarbonates and polyester carbonates.

20. Polysulfones, polyether sulfones and polyether ketones.

21. Crosslinked polymers derived from aldehydes on the one hand and phenols, ureas and melamines on the other hand, such as phenol/formaldehyde resins, urea/formaldehyde resins and melamine/formaldehyde resins.

22. Drying and non-drying alkyd resins.

23. Unsaturated polyester resins derived from copolyesters of saturated and unsaturated dicarboxylic acids with polyhydric alcohols and vinyl compounds as crosslinking agents, and also halogen-containing modifications thereof of low flammability.

24. Crosslinkable acrylic resins derived from substituted acrylates, for example epoxy acrylates, urethane acrylates or polyester acrylates.

25. Alkyd resins, polyester resins and acrylate resins crosslinked with melamine resins, urea resins, polyisocyanates or epoxy resins.

26. Crosslinked epoxy resins derived from polyepoxides, for example from bisglycidyl ethers or from cycloaliphatic diepoxides.

27. Natural polymers such as cellulose, rubber, gelatin and chemically modified homologous derivatives thereof, for example cellulose acetates, cellulose propionates and cellulose butyrates, or the cellulose ethers such as methyl cellulose; as well as rosins and their derivatives.

28. Blends of the aforementioned polymers (polyblends), for example PP/EPDM, Polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS, PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPO/HIPS, PPO/PA 6.6 and copolymers, PA/HDPE, PA/PP, PA/PPO.

29. Naturally occurring and synthetic organic materials which are pure monomeric compounds or mixtures of such compounds, for example mineral oils, animal and vegetable fats, oil and waxes, or oils, fats and waxes based on synthetic esters (e.g. phthalates, adipates, phosphates or trimellitates) and also mixtures of synthetic esters with mineral oils in any weight ratios, typically those used as spinning compositions, as well as aqueous emulsions of such materials.

30. Aqueous emulsions of natural or synthetic rubber, e.g. natural latex or latices of carboxylated styrene/butadiene copolymers.

The compounds of formula (I) are particularly suitable for improving the light stability, heat stability and stability to oxidation of polyolefins, particularly polyethylene and polypropylene.

The compounds of the formula (I) are especially suitable for the light stabilization of polypropylene thick sections.

The compounds of formula (I) can be used in mixtures with organic materials in various proportions depending on the nature of the material to be stabilised, on the end use and on the presence of other additives.

In general, it is appropriate to use, for example, 0.01 to 5% by weight of the compounds of formula (I), relative to the weight of the material to be stabilised, preferably between 0.05 and 1%.

In general, the compounds of formula (I) can be incorporated in the polymeric materials before, during or after the polymerisation or crosslinking of the said materials.

The compounds of formula (I) can be incorporated in the polymeric materials in the pure form or encapsulated in waxes, oils or polymers.

The compounds of formula (I) can be incorporated in the polymeric materials by various processes, such as dry mixing in the form of powder, or wet mixing in the form of solutions or suspensions or also in the form of a masterbatch; in such operations, the polymer can be used in the form of powder, granules, solutions, suspensions or in the form of latices.

The materials stabilised with the products of formula (I) can be used for the production of mouldings, films, tapes, monofilaments, fibres, surface coatings and the like.

If desired, other conventional additives for synthetic polymers, such as antioxidants, UV absorbers, nickel stabilisers, pigments, fillers, plasticisers, antistatic agents, flameproofing agents, lubricants, corrosion inhibitors and metal deactivators, can be added to the mixtures of the compounds of formula (I) with the organic materials.

Particular examples of additives which can be used in admixture with the compounds of formula (I) are:

1. Antioxidants

1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(α-methylcyclohexyl)-4,6-dimethylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol, 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6-(1'-methylundec-1'-yl)phenol, 2,4-dimethyl-6-(1'-methylheptadec-1'-yl)phenol, 2,4-dimethyl-6-( 1'-methyltridec-1'-yl)phenol and mixtures thereof.

1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-di-do-decylthiomethyl-4-nonylphenol.

1.3. Hydroquinones and alkylated hydroquinones, for example 2,6-di-tert-butyl-4methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol, 2,6-di-ten-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis-(3,5-di-tert-butyl-4-hydroxyphenyl) adipate.

1.4. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tert-butyl-4-methylphenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2-methylphenol), 4,4'-thiobis-(3,6-di-sec-amylphenol), 4,4'-bis-(2,6-dimethyl-4-hydroxyphenyl) disulfide.

1.5. Alkylidenebisphenols, for example 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(6-nonyl-4-methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis[6-(α-methylbenzyl)-4-nonylphenol], 2,2'-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol], 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-methylenebis(6-tert-butyl-2-methylphenol), 1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol, 1,1,3-tris(5-tert-butyl-4-hydroxy2-methylphenyl)butane, 1,1-bis(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis[3,3-bis(3'-tert-butyl-4'-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)dicyclopentadiene, bis[2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate, 1,1-bis-(3,5-dimethyl-2hydroxyphenyl)butane, 2,2-bis-(3,5-di-tert-butyl-4-hydroxyphenyl)propane, 2,2-bis-(5-tert-butyl-4-hydroxy2-methylphenyl)-4-n-dodecylmercaptobutane, 1,1,5,5-tetra-(5-tert-butyl-4-hydroxy2-methylphenyl)pentane.

1.6. O--, N- and S-benzyl compounds, for example 3,5,3',5'-tetra-tert-butyl-4,4'-dihydroxydibenzyl ether, octadecyl-4-hydroxy-3,5-dimethylbenzylmercaptoacetate, tris-(3,5-di-tert-butyl-4-hydroxybenzyl)amine, bis( 4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide, isooctyl-3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate.

1.7. Hydroxybenzylated malonates, for example dioctadecyl-2,2-bis-(3,5-di-tert-butyl-2-hydroxybenzyl)-malonate, di-octadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)-malonate, di-dodecylmercaptoethyl-2,2-bis-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate, bis[4-(1,1,3,3-tetramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.

1.8. Aromatic hydroxybenzyl compounds, for example 1,3,5-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6tetramethylbenzene, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.

1.9. Triazine Compounds, for example 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)1,3,5-triazine, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine, 1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate.

1.10. Benzylphosphonates, for example dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl-5-tert-butyl-4-hydroxy3-methylbenzylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.

1.11. Acylaminophenols, for example 4-hydroxylauranilide, 4-hydroxystearanilide, octyl N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.

1.12. Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.13. Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N, N'-bis-(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1 -phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.14 Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.15 Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.16. Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g. N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine.

2. UV absorbers and light stabilisers

2.1.2-(2'-Hydroxyphenyl)benzotriazoles, for example 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(5'-tert-butyl-2'-hydroxyphenyl)benzotriazole,2-(2'-hydroxy-5'-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-methylphenyl)-5-chloro-benzotriazole, 2-(3'-sec-butyl-5'-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-4'-octyloxyphenyl)benzotriazole, 2-(3',5'-di-tert-amyl-2'-hydroxyphenyl)benzotriazole, 2-(3',5'-bis-(α,α-dimethylbenzyl)-2'-hydroxyphenyl)benzotriazole, mixture of 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)-carbonylethyl]-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)carbonylethyl]-2'-hydroxyphenyl)benzotriazole, 2-(3'-dodecyl-2'-hydroxy-5'-methylphenyl)benzotriazole, and 2-(3'-tert-butyl-2'-hydroxy-5'-(2-isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2'-methylene-bis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazole-2-ylphenol]; the transesterification product of 2-[3'-tert-butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxyphenyl]-2H-benzotriazole with polyethylene glycol 300; [R--CH₂ CH₂ --COO(CH₂)], where R=3'-tert-butyl-4'-hydroxy-5'-2H-benzotriazol-2-ylphenyl.

2.2. 2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and 2'-hydroxy-4,4'-dimethoxy derivatives.

2.3. Esters of substituted and unsubstituted benzoic acids, as for example 4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol, bis(4-tert-butylbenzoyl) resorcinol, benzoyl resorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.

2.4. Acrylates, for example ethyl α-cyano-β,β-diphenylacrylate, isooctyl α-cyano-β,β-diphenylacrylate, methyl α-carbomethoxycinnamate, methyl α-cyano-β-methyl-p-methoxycinnamate, butyl α-cyano-β-methyl-p-methoxy-cinnamate, methyl α-carbomethoxy-p-methoxycinnamate and N-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline.

2.5. Nickel compounds, for example nickel complexes of 2,2'-thio-bis-[4-(1,1,3,3-tetramethylbutyl)phenol], such as the 1:1 or 1:2 complex, with or without additional ligands such as n-butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel dibutyldithiocarbamate, nickel salts of the monoalkyl esters, e.g. the methyl or ethyl ester, of 4-hydroxy-3,5-di-tert-butylbenzylphosphonic acid, nickel complexes of ketoximes, e.g. of 2-hydroxy-4-methylphenyl undecylketoxime, nickel complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additional ligands.

2.6. Sterically hindered amines, for example bis(2,2,6,6-tetramethyl-piperidyl)sebacate, bis(2,2,6,6-tetramethyl-piperidyl)succinate, bis(1,2,2,6,6-pentamethylpiperidyl)sebacate, bis(1,2,2,6,6-pentamethylpiperidyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid, the condensate of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1,3,5-triazine, tris(2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butane-tetracarboxylate, 1,1'-(1,2-ethanediyl)bis(3,3,5,5-tetramethylpiperazinone), 4-benzoyl-2,2,6,6tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethylpiperidine, bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate, 3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazasprio[4.5]decan-2,4-dion, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate, the condensate of N,N'-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-morpholino-2,6-dichloro-1,3,5-triazine, the condensate of 2-chloro-4,6-bis(4-n-butyl-amino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine and 1,2-bis(3-aminopropylamino)ethane, the condensate of 2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine and 1,2-bis-(3-aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione, 3-dodecyl-1-(2,2,6,6-tetramethyl-4piperidyl)pyrrolidin-2,5-dione, 3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione.

2.7. Oxamides, for example 4,4'-dioctyloxyoxanilide, 2,2'-dioctyloxy-5,5'-di-tert-butoxanilide, 2,2'-didodecyloxy-5,5'-di-tert-butoxanilide, 2-ethoxy-2'-ethoxanilide, N,N'-bis(3-dimethylaminopropyl)oxamide, 2-ethoxy-5-tert-butyl-2'-ethoxanilide and its mixture with 2-ethoxy-2'-ethyl-5,4'-di-tert-butoxanilide and mixtures of ortho- and paramethoxy-disubstituted oxanilides and mixtures of o- and p-ethoxy-disubstituted oxanilides.

2.8.2-(2-Hydroxyphenyl)-1,3,5-triazines, for example 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4-methylphenyl)-1,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2hydroxy-3-butyloxy-propoxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1,3,5-triazine.

3. Metal deactivators, for example N,N'-diphenyloxamide, N-salicylal-N'-salicyloyl hydrazine, N,N'-bis(salicyloyl) hydrazine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl) hydrazine, 3-salicyloylamino-1,2,4-triazole, bis(benzylidene)oxalyl dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide, N,N'-diacetyladipoyl dihydrazide, N,N'-bis(salicyloyl)oxalyl dihydrazide, N,N'-bis(salicyloyl)thiopropionyl dihydrazide.

4. Phosphites and phosphonites, for example triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)-pentaerythritol diphosphite, diisodecyloxypentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tris(tert-butylphenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz[d,g]-1,3,2-dioxaphosphocin, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocin, bis(2,4-di-tert-butyl-6methylphenyl)methylphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)ethylphosphite.

4bis. Hydroxylamines, for example dibenzylhydroxylamine, dioctylhydroxylamine, didodecylhydroxylamine, ditetradecylhydroxylamine, dihexadecylhydroxylamine, dioctadecylhydroxylamine, 1-hydroxy-2,2,6,6-tetramethyl-4-piperidyl benzoate or bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate.

5. Peroxide scavengers, for example esters of β-thiodipropionic acid, for example the lauryl, stearyl, myristyl or tridecyl esters, mercaptobenzimidazole or the zinc salt of 2-mercaptobenzimidazole, zinc dibutyldithiocarbamate, dioctadecyl disulfide, pentaerythritol tetrakis(β-dodecylmercapto)propionate.

6. Polyamide stabilisers, for example, copper salts in combination with iodides and/or phosphorus compounds and salts of divalent manganese.

7. Basic co-stabilisers, for example, melamine, polyvinylpyrrolidone, dicyandiamide, triallyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali metal salts and alkaline earth metal salts of higher fatty acids for example calcium stearate, zinc stearate, magnesium behenate, magnesium stearate, sodium ricinoleate and potassium palmitate, antimony pyrocatecholate or tin pyrocatecholate.

8. Nucleating agents, for example, 4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid.

9. Fillers and reinforcing agents, for example, calcium carbonate, silicates, glass fibres, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxydes, carbon black, graphite.

10. Other additives, for example, plasticisers, lubricants, emulsifiers, pigments, optical brighteners, flameproofing agents, antistatic agents and blowing agents.

11. Benzofuranones and indolinones, for example those disclosed in U.S. Pat. Nos. 4,325,863, 4,338,244 or U.S. Pat. No. 5,175,312, or 3-[4-(2-acetoxyethoxy)phenyl]-5,7-di-tert-butyl-benzofuran-2-one 5,7-di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phenyl]benzofuran-2-one, 3,3'-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2-one], 5,7-di-tert-butyl-3-(4-ethoxyphenyl )benzofuran-2-one, 3-(4-acetoxy-3,5-dimethylphenyl )-5,7-di-tert-butyl-benzofuran-2-one, 3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butyl-benzofuran-2-one.

The compounds of the formula (I) can also be used as stabilizers, especially as light stabilizers, for almost all materials known in the art of photographic reproduction and other reproduction techniques as e.g. described in Research Disclosure 1990, 31429 (pages 474 to 480).

In order to illustrate the present invention more clearly, there will now be described some examples of the preparation and of the use of the compounds of formula (I); these examples are given purely by way of illustration and do not imply any limitation.

EXAMPLE 1

Preparation of the compound of formula ##STR85##

A mixture of 30 g (99.2 mmols) of dodecyldiethoxymethylsilane, 34.3 g (218 mmols) of 2,2,6,6-tetramethyl-4-piperidinol and 1.4 ml of Ti(IV) isopropoxide in 120 ml of toluene is heated to a refluxing temperature for 6 hours, with removal of the ethanol formed. Thereafter, the mixture is heated for a further 2 hours, whilst distilling off 60 ml of toluene.

After cooling to ambient temperature, the reaction mixture is diluted with 30 ml of toluene, washed with water, dried over anhydrous Na₂ SO₄ and evaporated under reduced pressure. The residue is distilled in vacuo: a colourless oil of boiling point 236°-238° C./1.5 mbar is obtained.

Analysis for C₃₁ H₆₄ N₂ O₂ Si Calculated: C=70.93%; H=12.29%; N=5.34% Found: C=70.73%; H=12.28%; N=5.35%

EXAMPLE 2

The same compound as in Example 1 is prepared by adding 15 g (53 mmols) of dichlorododecylmethylsilane to a solution of 18.4 g (117 mmols) of 2,2,6,6-tetramethyl-4-piperidinol in 80 ml of triethylamine and heating to the reflux temperature for 1 hour.

After cooling to ambient temperature, the precipitate formed is filtered off, the excess triethylamine is evaporated and the residue is purified by distillation in vacuo, giving the desired product as a colourless oil with boiling point 236°-238° C./1.5 mbar.

Analysis for C₃₁ H₆₄ N₂ O₂ Si Calculated: C=70.93%; H=12.29%; N=5.34% Found: C=70.82%; H=12.27%; N=5.33%

EXAMPLE 3

Following the process described in Example 1, 19.9 g (60 mmols) of 4-[3-(diethoxymethylsilyl)propoxy]-2,2,6,6-tetramethylpiperidine are caused to react with 20.8 g (132 mmols) of 2,2,6,6-tetramethyl-4-piperidinol in 100 ml of xylene in the presence of 1.5 ml of Ti(IV) isopropoxide.

After distillation, the compound of formula ##STR86## is obtained as a colourless oil of boiling point 195°-197° C./0.06 mbar.

Analysis for C₃₁ H₆₃ N₃ O₃ Si Calculated: C=67.22%; H=11.46%; N=7.59% Found: C=66.94%; H=11.43%; N=7.54%

EXAMPLE 4

Following the process described in Example 1,100.2 g (290 mmols) of 4-[3-(diethoxymethylsilyl)propoxy]-1,2,2,6,6-pentamethylpiperidine are caused to react with 109.3 g (638 mmols) of 1,2,2,6,6-pentamethyl-4-piperidinol in 300 ml of xylene in the presence of 2.5 ml of Ti(IV) isopropoxide.

After distillation, the compound of formula ##STR87## is obtained as a colourless oil of boiling point 191°-193° C./0.5 mbar. Analysis for C₃₄ H₆₉ N₃ O₃ Si Calculated: C=68.52%; H=11.67%; N=7.05% Found: C=68.11%; H=11.65%; N=7.06%

EXAMPLE 5

Following the process described in Example 1, 40 g (92.9 mmols) of 3-(diethoxymethylsilyl)propylbutyl(2,2,6,6-tetramethyl-4-piperidyl)carbamate are reacted with 32.1 g (204.3 mmols) of 2,2,6,6-tetramethyl-4-piperidinol in 120 ml of toluene in the presence of 2 ml of Ti(IV) isopropoxide.

After distillation, the compound of formula ##STR88## is obtained as a colourless oil of boiling point 249°-251° C./0.02 mbar.

Analysis for C₃₆ H₇₂ N₄ O₄ Si Calculated: C=66.21%; H=11.11%; N=8.58% Found: C=66.07%; H=11.10%; N=8.51%

EXAMPLE 6

Following the process described in Example 1, 20 g (90.3 mmols) of 3-(triethoxysilyl)propanamine are reacted with 46.9 g (298 mmols) of 2,2,6,6-tetramethyl-4-piperidinol in 120 ml of toluene in the presence of 2 ml of Ti(IV) isopropoxide.

After distillation, the compound of formula ##STR89## is obtained as a colourless oil of boiling point 175°-177° C./0.05 mbar.

Analysis for C₃₀ H₆₂ N₄ O₃ Si Calculated: C =64.93%; H=11.26%; N=10.10% Found: C=64.87%; H=11.28%; N=10.07%

EXAMPLE 7

Following the process described in Example 1, 30 g (75 mmols) of 3-[3-(diethoxymethylsilyl)propyl]-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione are reacted with 26 g (165 mmols) of 2,2,6,6-tetramethyl-4-piperidinol in 120 ml of toluene in the presence of 1.5 ml of Ti(IV) isopropoxide.

After crystallisation from n-hexane, the compound of formula ##STR90## is obtained as a white powder melting at 50°-52° C.

Analysis for C₃₃ H₆₃ N₅ O₄ Si Calculated: C=63.73%; H=10.21%; N=11.26% Found: C=63.18%; H=10.06%; N=11.20%

EXAMPLE 8

Following the process described in Example 1, 41.6 g (120 mmols) of ethyl 11-(diethoxymethylsilyl)undecanoate are reacted with 62.3 g (396 mmols) of 2,2,6,6-tetramethyl-4-piperidinol in 180 ml of xylene in the presence of 2.5 ml of Ti(IV) isopropoxide.

After distillation of the excess 2,2,6,6-tetramethyl-4-piperidinol, the residue is taken up in toluene and the mixture is washed with water.

After separating off the organic phase and evaporating it at 80° C. in vacuo (1.3 mbar), the compound of formula ##STR91## is obtained as a very dense colourless oil.

Analysis for C₃₉ H₇₇ N₃ O₄ Si Calculated: C=68.87%; H=11.41%; N=6.18% Found: C=68.87%; H=11.40%; N=6.14%

EXAMPLE 9

Following the process described in Example 1, 41.6 g (120 mmols) of ethyl 11-(diethoxymethylsilyl)undecanoate are caused to react with 67.8 g (396 mmols) of 1,2,2,6,6-pentamethyl-4-piperidinol in 180 ml of xylene in the presence of 2.5 ml of Ti(IV) isopropoxide.

After distillation of the excess 1,2,2,6,6-pentamethyl-4-piperidinol, the compound of the formula ##STR92## is obtained as a colourless viscous oil.

Analysis for C₄₂ H₈₃ N₃ O₄ Si Calculated: C=69.85%; H=11.58%; N=5.82% Found: C-69.36%; H=11.52%; N=5.79%

EXAMPLE 10

Following the process described in Example 1, 40 g (87.6 mmols) of 11-(diethoxymethylsilyl)-N-(2,2,6,6-tetramethyl-4-piperidyl)undecanamide are caused to react with 30.3 g (192.6 mmols) of 2,2,6,6-tetramethyl-4-piperidinol in 120 ml of toluene in the presence of 1.5 ml of Ti(IV) isopropoxide.

After distillation, the compound of formula ##STR93## is obtained as a straw-coloured oil of boiling point 278°-280° C./0.01 mbar.

Analysis for C₃₉ H₇₈ N₄ O₃ Si Calculated: C=68.97%; H=11.58%; N=8.25% Found: C=69.00%; H=11.61%; N=8.21%

EXAMPLE 11

Following the process described in Example 1, 16.7 g (50 mmols) of diethyl [3-(diethoxymethylsilyl)propyl]malonate are caused to react with 34.6 g (220 mmols) of 2,2,6,6-tetramethyl-4-piperidinol in 150 ml of mesitylene in the presence of 2 ml of Ti(IV) isopropoxide.

After purification by column chromatography over silica gel (eluant: tetrahydrofuran), a compound of formula ##STR94## is obtained as a dense straw-coloured oil.

Analysis for C₄₃ H₈₂ N₄ O₆ Si Calculated: C=66.28%; H=10.61%; N=7.19% Found: C=65.77%; H=10.57%; N=7.14%

EXAMPLE 12

Following the process described in Example 1, 40 g (53.8 mmols) of N,N'-bis[3-(diethoxymethylsilyl)propyl]-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexanediamine are caused to react with 37.2 g (236.7 mmols) of 2,2,6,6-tetramethyl-4-piperidinol in 150 ml of toluene in the presence of 2 ml of Ti(IV) isopropoxide.

After purification by column chromatography using silica gel (eluant: a 2/1 mixture of tetrahydrofuran and methanol), the compound of formula ##STR95## is obtained as a resin of pale yellow colour.

Analysis for C₆₈ H₁₃₈ N₈ O₄ Si₂ Calculated: C=68.75%; H=11.71%; N=9.43% Found: C=68.60%; H=11.59%; N=9.36%

EXAMPLE 13

Following the process 1described in Example 1, 23.2 g (60 mmol) of octadecyl diethyloxy methyl silane are caused to react with 20.8 g (132 mmol) of 2,2,6,6-tetramethyl-4-piperidinol in 100ml of xylene in the presence of 1.5 ml of Ti (IV)isopropoxide.

After distillation of the excess of the alcohol the residue is taken up in toluene and the mixture is washed with water. After separating off the organic phase and evaporating it at 80° C. in vacuo (1.3 mbar), the compound of the formula ##STR96## is obtained as a white solid with m.p. 38°-40 ° C.

Analysis for C₃₇ H₇₆ N₂ O₂ Si Calculated: C=72.96%; H=12.58%; N=4.60% Found: C=72.35%; H=12.57%; N=4.58%

EXAMPLE 14

Following the process described in Example 1, 30 g (99.2 mmol) of dodecyldiethoxy methyl silane are caused to react with 37.3 g (218 mmol) of 1,2,2,6,6-pentamethyl-4-piperidinol in 120 ml of xylene in the presence of 1.7 ml of Ti(IV)isopropoxide.

After distillation the compound of the formula ##STR97## is obtained as a colourless oil of boiling point 228° C./1 mbar.

Analysis for C₃₃ H₆₈ N₂ O₂ Si Calculated: C=71.67%; H=12.39%; N=5.07% Found: C=71.05%; H=12.34%; N=5.06%

EXAMPLE 15

Following the process described in Example 1, 21.7 g (60 mmol) of 4(3-triethoxysilyl propoxy)-2,2,6,6-tetramethyl piperidine are caused to react with 31.13 g (198 mmol) of 2,2,6,6-tetramethyl-4-piperidinol in 130 ml of xylene in the presence of 2.0 ml of Ti(IV)isopropoxide.

After distillation the compound of the formula ##STR98## is obtained as a colourless oil of boiling point 230° C./0.01 mbar.

Analysis for C₃₉ H₇₈ N₄ O₄ Si Calculated: C=67.38%; H=11.31%; N=8.06% Found: C=67.31%; H=11.25%; N=8.00%

EXAMPLE 16

Following the process described in Example 1, 45.2 g (120 mmol) of ethyl 11 (triethoxysilyl) undecanoate are caused to react with 83.0 g (528 mmol) of 2,2,6,6-tetramethyl-4-piperidinol in 200 ml of xylene in the presence of 3.0 ml of Ti(IV)isopropoxide.

After distillation of the excess of 2,2,6,6-tetramethyl-4-piperidinol the residue is taken up in toluene and the mixture is washed with water. After separating off the organic phase and evaporating it at 80° C. in vacuo (1.3 mbar), the compound of the formula ##STR99## is obtained as a very dense colourless oil.

Analysis for C₄₇ H₉₂ N₄ O₅ Si Calculated: C=68.73%; H=11.29%; N=6.82% Found: C=68.74%; H=11.30%; N=6.82%

EXAMPLE 17

Following the process described in Example 1, 33.3 g (100 mmol) of dodecyl triethoxy silane are caused to react with 51.9 g (330 mmol) of 2,2,6,6-tetramethyl-4-piperidinol in 150 ml of xylene in the presence of 2.5 ml of Ti(IV) isopropoxide.

After distillation the compound of the formula ##STR100## is obtained as a colourless oil of boiling point 194° C./0.01 mbar.

Analysis for C₃₉ H₇₉ N₃ O₃ Si Calculated: C=70.32%; H=11.95%; N=6.31% Found: C=70.31%; H=11.96%; N=6.31%

EXAMPLE 18

Following the process described in Example 2, 36 g (100 mmol) of trichlorohexadecylsilane are caused to react with 53 g (310 mmol) of 1,2,2,6,6-pentamethyl-4-piperidinol in 300 ml of dioxane in the presence of 33.3 g (330 ml) of triethylamine.

After cooling to room temperature, the mixture is washed with water and extracted with ethyl ether. After separating off the organic phase and evaporating in vacuo, the compound of the formula ##STR101## is obtained as a yellowish oil.

Analysis for C₄₆ H₉₃ N₃ O₃ Si Calculated: C=72.28%; H=12.26%; N=5.50% Found: C=72.84%; H=12.24%; N=5.36%

EXAMPLE 19

Following the process described in Example 1, 17.9 g (20 mmol) of N,N'-tetrakis[3(diethoxy methyl silyl)propyl]sebacamide are caused to react with 27.6 g (176 mmol) of 2,2,6,6-tetramethyl-4-piperidinol in 100 ml of xylene in the presence of 1.5 ml of Ti(IV) isopropoxide.

After purification by column chromatography the compound of the formula ##STR102## is obtained as a yellowish resin.

Analysis for C₉₈ H₁₉₆ N₁₀ O₁₀ Si4 Calculated: C =65.87%; H=11.05%; N=7.83% Found: C=65.81%; H=11.03%; N=7.79%

EXAMPLE 20

Following the process described in Example 1, 13 g (20 mmol) of 1,3,5-tris[3(diethoxy methyl silyl)propyl]-[1,3,5-triazinane-2,4,6-trione] are caused to react with 20.8 g (132 mmol) of 2,2,6,6-tetramethyl-4-piperidinol in 100 ml of xylene in the presence of 1.5 ml of Ti(IV) isopropoxide.

After purification by washing with water and drying, the compound of the formula ##STR103## is obtained as a yellowish resin.

Analysis for C₆₉ H₁₃₅ N₉ O₉ Si₃ Calculated: C=62.83%; H=10.32%; N=9.56% Found: C=62.29%; H=10.20%; N=9.41%

EXAMPLE 21

(light stabilising action in polypropylene plaques) 1 g of each of the compounds indicated in Table 1, 1 g of tris(2,4-di-t-butylphenyl) phosphite, 0.5 g of pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1 g of calcium stearate and 1 g of Filofin Blue G are mixed in a slow mixer with 1000 g of polypropylene powder having a melt index=4 g/10 min (measured at 230° C. and 2.16 kg).

The mixtures obtained are extruded at a temperature of 200°-230° C. to give polymer granules which are subsequently converted to plaques of 2 mm thickness by means of injection moulding at 200°-220° C.

The plaques obtained are exposed in a Weather-O-Meter model 65 WR (ASTM D2565-85) with a black panel temperature of 63° C., until surface crazing (chalking) starts.

By way of comparison, a polypropylene plaque prepared under the same conditions as indicated above, but without the addition of the compounds of the invention, is exposed.

Table 1 shows the exposure time in hours required to bring about this start of chalking.

                  TABLE 1                                                          ______________________________________                                         Stabiliser        T chalking (hours)                                           ______________________________________                                         Without stabiliser                                                                                750                                                         Compound of Example 1                                                                            4260                                                         Compound of Example 3                                                                            4900                                                         Compound of Example 4                                                                            3930                                                         Compound of Example 5                                                                            3310                                                         Compound of Example 7                                                                            4050                                                         Compound of Example 10                                                                           3820                                                         Compound of Example 11                                                                           4260                                                         Compound of Example 12                                                                           3400                                                         Compound of Example 13                                                                           3200                                                         Compound of Example 16                                                                           >3900                                                        Compound of Example 17                                                                           >3900                                                        ______________________________________                                    

EXAMPLE 22

(light stabilising action in polypropylene tapes)

1 g of each of the compounds indicated in Table 2, 1.0 g of tris(2,4-di-t-butylphenyl)phosphite, 0.5 g of pentaerythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] and 1 g of calcium stearate are mixed in a slow mixer with 1000 g of polypropylene powder having a melt index =2 g/10 min (measured at 230° C. and 2.16 kg).

The mixtures are extruded at 200°-220° C. to give polymer granules which are subsequently converted to stretched tapes of 50 gm thickness and 2.5 mm width, using a semi-industrial type of apparatus (Leonard-Sumirago (VA) Italy), and working under the following conditions:

    ______________________________________                                         Extruder temperature: 210-230° C.                                       Head temperature:     240-260° C.                                       Stretch ratio:        1:6                                                      ______________________________________                                    

The tapes thus prepared are mounted on white card and exposed in a Weather-O-Meter 65 WR (ASTM D2565-85) with a black panel temperature of 63° C.

The residual tenacity is measured, by means of a constant velocity tensometer, on samples taken after various light exposure times; from this, the exposure time (in hours) required to halve the initial tenacity (T₅₀) is measured. By way of comparison, tapes prepared under the same conditions as indicated above, but without the addition of the stabilisers of the present invention, are exposed.

The results obtained are shown in Table 2.

                  TABLE 2                                                          ______________________________________                                         Stabiliser         T.sub.50 (hours)                                            ______________________________________                                         Without stabiliser  530                                                        Compound of Example 3                                                                             4810                                                        Compound of Exwnple 7                                                                             4950                                                        Compound of Example 10                                                                            3680                                                        Compound of Example 12                                                                            4210                                                        Compound of Example 13                                                                            >3700                                                       Compound of Example 16                                                                            >3700                                                       Compound of Example 17                                                                            >4070                                                       ______________________________________                                     

What is claimed is:
 1. A compound of formula (I) ##STR104## in which R₁ is hydrogen, C₁ -C₈ alkyl, OH, CH₂ CN, C₁ -C₁₈ alkoxy, C₅ -C₁₂ cycloalkoxy, C₃ -C₆ alkenyl, C₇ -C₉ phenylalkyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl, or aliphatic C₁ -C₈ acyl;R₂ and R₃, which may be identical or different, are C₁ -C₈ alkyl, phenyl, C₁ -C₈ alkoxy or a group of formula (II) ##STR105## n is 1, 2, 3 or 4; if n is 1, R₄ is C₁₂ -C₁₈ alkyl, C₅ -C₁₂ cycloalkyl which is unsubstituted or substituted with 1, 2 or 3 C₁ -C₄ alkyl or one of the groups of formulae (IIIa)-(IIId) ##STR106## in which R₅ is C₁ -C₁₈ alkyl, C₃ -C₃₀ alkyl interrupted by one or more oxygen atoms, C₅ -C₁₂ cycloalkyl which is unsubstituted or substituted with 1, 2 or 3 C₁ -C₄ alkyl, phenyl which is unsubstituted or substituted with 1, 2 or 3 C₁ -C₄ alkyl or with C₁ -C₄ alkoxy, C₇ -C₉ phenylalkyl which is unsubstituted or substituted on the phenyl with 1, 2 or 3 C₁ -C₄ alkyl, a group of formula (IV) ##STR107## where R₁₄ has any one of the meanings given for R₁, or R₅ is aliphatic, cycloaliphatic or aromatic acyl containing not more than 22 carbon atoms or a group ##STR108## where R₁₅ and R₁₆, which may be identical or different, are hydrogen, C₁ -C₁₈ alkyl, C₅ -C₁₂ cycloalkyl which is unsubstituted or substituted with 1, 2 or 3 C₁ -C₄ alkyl, C₇ -C₉ phenylalkyl which is unsubstituted or substituted on the phenyl with 1, 2 or 3 C₁ -C₄ alkyl or a group of formula (IV), or ##STR109## is a heterocyclic group with 5-7 members, or one of the groups of formulae (Va)-(Vc) ##STR110## in which R₁₄ is as defined above, X₂ is --CH₂ CH₂ --, --CO--, --COCO-- or --COCH₂ CO-- and q is zero or 1; R₆ is C₂ -C₁₈ alkylene; R₇ and R₈, which may be identical or different, are as defined above for R₁₅ and R₁₆, or R₇ is also (C₁ -C₁₈ alkoxy)carbonyl or aliphatic, cycloaliphatic or aromatic acyl containing not more than 22 carbon atoms, or ##STR111## is a heterocyclic group having 5-7 members or one of the groups of formulae (Va)-(Vc) or one of the groups of formulae (VIa)-(VIc) ##STR112## in which X₃ is --O-- or ##STR113## where R₂₀ is as defined above for R₁₅ and R₁₆ ; R₁₇ is as defined above for R₇ or R₁₇ --X₃ -- is hydrogen or a nitrogen-containing heterocyclic group having 5-7 members, with the free valency on the nitrogen atom, or the group ##STR114## group, R₁₄ is as defined above, R₁₈ is hydrogen, methyl, acetyl or benzyl and R₁₉ is hydrogen or C₁ -C₃₀ alkyl; R₉ is C₃ -C₁₈ alkylene; R₁₀ is C₁ -C₁₈ alkyl, C₅ -C₁₂ cycloalkyl which is unsubstituted or substituted with 1, 2 or 3 C₁ -C₄ alkyl, C₇ -C₉ phenylalkyl which is unsubstituted or substituted on the phenyl with 1, 2 or 3 C₁ -C₄ alkyl or a group of formula (IV), or R₁₀ is a group of formula (VII) ##STR115## with R₁, R₂, R₃ and R₆ as defined above; X₁ is as defined above for X₃ or R₁₀ X₁ -- is a nitrogen-containing heterocyclic group having 5-7 members, with the free valency on the nitrogen atom, or one of the groups of formulae (Va)-(Vc) or (VIa)-(VIc); p is 1, 2 or 3 and, if p is 1, R₁₁ is C₂ -C₁₈ alkylene, if p is 2, R₁₁ is C₂ -C₂₀ alkanetriyl, C₅ -C₇ cycloalkanetriyl or C₇ -C₉ bicycloalkanetriyl and, if p is 3, R₁₁ is C₃ -C₆ alkanetetrayl; R₁₂ is as defined above for R₁₅ and R₁₆ and R₁₃ is a direct bond or C₁ -C₃₀ alkylene; if n is 2, R₄ is C₂ -C₁₂ alkylene, C₄ -C₂₂ alkylene interrupted by an oxygen atom or by an ##STR116## group, where R₂₁ is as defined above for R₇, or R₄ is one of the groups of formulae (VIIIa)-(VIIIc) ##STR117## in which X₄ and X₅, which may be identical or different, are --O-- or ##STR118## where R₂₈ is as defined above for R₇ ; R₂₂ is C₂ -C₁₈ alkylene or a --C_(r) H_(2r) CO-- group, where r is an integer from 2 to 18 and the carbonyl group is bonded to X₄ or X₅ ; R₂₃ is C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms, C₅ -C₇ cycloalkylene, C₅ -C₇ cycloalkylenedi(C₁ -C₄ alkylene), C₁ -C₄ alkylenedi(C₅ -C₇ cycloalkylene), isopropylidenedicyclohexylene, phenylene which is unsubstituted or substituted by 1 or 2 C₁ -C₄ alkyl, phenylenedi(C₁ -C₄ alkylene), C₂ -C₄ alkylidenediphenylene or a group of formula (IXa) or (IXb) ##STR119## in which R₂₉ is hydrogen or C₁ -C₄ alkyl and R₃₀ is C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms or phenylenedi(C₁ -C₄ alkylene) or, if R₂₂ is C₂ -C₁₈ alkylene, R₂₃ is also carbonyl, a ##STR120## group, where R₃₁ is a direct bond, C₁ -C₁₂ alkylene, C₂ -C₂₀ alkylidene, C₅ -C₇ cycloalkylene or phenylene which is unsubstituted or substituted with 1 or 2 C₁ -C₄ alkyl, R₃₂ and R₃₄ are C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms, C₅ -C₇ cycloalkylene, C₅ -C₇ cycloalkylenedi(C₁ -C₄ alkylene), C₁ -C₄ alkylenedi(C₅ -C₇ cycloalkylene), C₂ -C₄ alkylenedi(C₅ -C₇ cycloalkylene ) or a group of formula (IXa) or (IXb), and R₃₃ and R₃₅, which may be identical or different, are as defined above for R₁₅ and R₁₆, or the --R₂₃ --X₅ -- group is a ##STR121## group or the --X₄ --R₂₃ --X₅ -- group is a ##STR122## group with X₂ as defined above or a ##STR123## group; R₂₄ is C₃ -C₁₈ alkylene; X₆ and X₇, which may be identical or different, are as defined above for X₄ and X₅ ; R₂₅ is C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms, C₅ -C₇ cycloalkylene, C₅ -C₇ cycloalkylenedi(C₁ -C₄ alkylene), C₁ -C₄ alkylenedi(C₅ -C₇ cycloalkylene ), carbonyl, or a ##STR124## group, with R₃₁ and R₃₂ as defined above, or the --X₆ --R₂₅ --X₇ -- group is an ##STR125## group, where R₃₆ is as defined above for R₇ and X₂ is as defined above, or the ##STR126## group is a ##STR127## group; R₂₆ is C₃ -C₁₈ alkylene or a group of formula (X) ##STR128## where R₃₇ is C₂ -C₁₂ alkylene, C₄ -C₁₂ alkylene interrupted by one or more oxygen atoms, C₅ -C₇ cycloalkylene, C₅ -C₇ cycloalkylenedi(C₁ -C₄ alkylene) or C₁ -C₄ alkylenedi(C₅ -C₇ cycloalkylene) and R₂₇ is a direct bond or C₁ -C₃₀ alkylene; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe) ##STR129## which R₃₈ is C₃ -C₁₂ alkanetriyl or aliphatic or aromatic triacyl containing not more than 12 carbon atoms; R₃₉ is C₂ -C₁₈ alkylene or, if R₃₈ is C₃ -C₁₂ alkanetriyl, R₃₉ is also a --C_(s) H_(2s) CO-- group where s is an integer from 2 to 18 and the carbonyl group is bonded to the oxygen atom; R₄₀, R₄₁ and R₄₂, which may be identical or different, are C₃ -C₁₈ alkylene or R₄₀ is also a ##STR130## group, where the carbonyl group is bonded to the nitrogen atom and R₄₅ is C₂ -C₁₈ alkylene; R₄₃ is C₃ -C₁₈ alkylene and R₄₄ is C₂ -C₆ alkylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc) ##STR131## in which R₄₆ is C₄ -C₆ alkanetetrayl or aliphatic or aromatic tetraacyl containing not more than 12 carbon atoms; R₄₇ is C₂ -C₁₈ alkylene or, if R₄₆ is C₄ -C₁ -C₁₂ alkanetetrayl, R₄₇ is also a --C_(s) H_(2s) CO-- group as defined above; R₄₈ is C₃ -C₁₈ alkylene and R₄₉ is as defined above for R₂₅.
 2. A compound of formula (I) according to claim 1, in which R₁ and R₁₄ are hydrogen, C₁ -C₄ alkyl, OH, C₆ -C₁₂ alkoxy, C₅ -C₈ cycloalkoxy, allyl, benzyl or acetyl.
 3. A compound of formula (I) according to claim 1, in which R₂ and R₃, which may be identical or different, are C₁ -C₄ alkyl, C₁ -C₄ alkoxy or a group of formula (II), n is 1,2,3 or 4 and, if n is 1, R₄ is C₁₂ -C₁₈ alkyl, C₅ -C₈ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, or one of the groups of the formulae (IIIa)-(IIId) in which R₅ is C₄ -C₁₈ alkyl, C₄ -C₂₈ alkyl interrupted by one or more oxygen atoms, C₅ -C₈ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, phenyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl or with C₁ -C₄ alkoxy, benzyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl, a group of formula (IV),aliphatic, cycloaliphatic or aromatic acyl containing not more than 20 carbon atoms or an ##STR132## group, where R₁₅ and R₁₆, which may be identical or different, are hydrogen, C₁ -C₁₈ alkyl, C₅ -C₈ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl or a group of formula (IV), or ##STR133## is 4-morpholinyl or one of the groups of formulae (Va)-(Vc), in which X₂ is --CH₂ CH₂ -- or --CO-- or --COCO-- and q is zero or 1; R₆ is C₂ -C₁₈ alkylene; R₇ and R₈, which may be identical or different, are as defined above for R₁₅ and R₁₆, or R₇ is also (C₂ -C₁₈ alkoxy)carbonyl or aliphatic, cycloaliphatic or aromatic acyl containing not more than 20 carbon atoms, or ##STR134## is 4-morpholinyl or one of the groups of formulae (Va)-(Vc) or one of the groups of formulae (VIa)-(VIc) in which X₃ is --O-- or ##STR135## where R₂₀ is as defined above for R₁₅ and R₁₆ ; R₁₇ is as defined above for R₇ or R₁₇ X₃ -- is hydrogen or 4-morpholinyl, R₁₈ is hydrogen or methyl and R₁₉ is hydrogen or C₃ -C₂₈ alkyl; R₉ is C₃ -C₁₈ alkylene; R₁₀ is C₂ -C₁₈ alkyl, C₅ -C₈ cycloalkyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl which is unsubstituted or substituted on the phenyl with 1,2 or 3 C₁ -C₄ alkyl, a group of formula (IV) or a group of formula (VII), X₁ is as defined above for X₃ or R₁₀ X₁ -- is 4-morpholinyl or one of the groups of formulae (Va)-(Vc) or (VIa)-(VIc); p is 1,2 or 3 and, if p is 1, R₁₁ is C₂ -C₁₇ alkylene and, if p is 2, R₁₁ is C₂ -C₂₀ alkanetriyl or C₆ -C₇ cycloalkanetriyl and, if p is 3, R₁₁ is propanetetrayl; R₁₂ is as defined above for R₁₅ and R₁₆ and R₁₃ is a direct bond or C₃ -C₂₈ alkylene; if n is 2, R₄ is C₂ -C₈ alkylene or C₄ -C₂₁ alkylene interrupted by an oxygen atom or by an ##STR136## group, where R₂₁ is as defined above for R₇, or R₄ is one of the groups of formulae (VIIIa)-(VIIIc), in which X₄ and X₅, which may be identical or different, are --O-- ##STR137## where R₂₈ is as defined above for R₇ ; R₂₂ is C₂ -C₁₈ alkylene or a C_(r) H_(2r) CO-- group, where r is an integer from 2 to 17 and the carbonyl group is bonded to X₄ or X₅ ; R₂₃ is C₂ -C₁₀ alkylene or C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, isopropylidenedicyclohexylene, phenylene, phenylenedimethylene, isopropylidenediphenylene or a group of formula (IXa) or (IXb) in which R₂₉ is hydrogen or methyl and R₃₀ is C₂ -C₁₀ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms or phenylenedimethylene or, if R₂₂ is C₂ -C₁₈ alkylene, R₂₃ is also carbonyl or a ##STR138## group, where R₃₁ is C₁ -C₁₀ alkylene, C₃ -C₁₉ alkylidene, cyclohexylene or phenylene, R₃₂ and R₃₄ are C₂ -C₁₀ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, isopropylidenedicyclohexylene or a group of formula (IXa) or (IXb) and R₃₃ and R₃₅, which may be identical or different, are as defined above for R₁₅ and R₁₆ or the --R₂₃ --X₅ -- group is a ##STR139## group or the --X₄ --R₂₃ --X₅ -- group is a 1,4-piperazinediyl group or a ##STR140## group; R₂₄ is C₃ -C₁₈ alkylene; X₆ and X₇, which may be identical or different, are as defined above for X₄ and X₅, R₂₅ is C₂ -C₁₀ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, carbonyl or a ##STR141## group, with R₃₁ and R₃₂ as defined above, or the --X₆ --R₂₅ --X₇ -- group is an ##STR142## group, where R₃₆ is as defined above for R₇ ; R₂₆ is C₃ -C₁₈ alkylene or a group of formula (X), where R₃₇ is C₂ -C₁₀ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene or methylenedicyclohexylene and R₂₇ is a direct bond or C₃ -C₂₈ alkylene; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe), in which R₃₈ is C₃ -C₁₀ alkanetriyl or aliphatic or aromatic triacyl containing not more than 10 carbon atoms; R₃₉ is C₂ -C₁₈ alkylene or, if R₃₈ is C₃ -C₁₀ alkanetriyl, R₃₉ is also a --C_(s) H_(2s) CO-- group, where s is an integer from 2 to 17 and the carbonyl group is bonded to the oxygen atom; R₄₀, R₄₁ and R₄₂, which may be identical or different, are C₃ -C₁₈ alkylene or R₄₀ is also a ##STR143## group, where the carbonyl group is bonded to the nitrogen atom and R₄₅ is C₂ -C₁₈ alkylene; R₄₃ is C₃ -C₁₁ alkylene and R₄₄ is C₂ -C₅ alkylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc) in which R₄₆ is C₄ -C₆ alkanetetrayl or aliphatic or aromatic tetraacyl containing not more than 10 carbon atoms, R₄₇ is C₂ -C₁₈ alkylene or, if R₄₆ is C₄ -C₆ alkanetetrayl, R₄₇ is also a --C_(s) H_(2s) CO-- group as defined above; R₄₈ is C₃ -C₁₁ alkylene and R₄₉ is as defined above for R₂₅.
 4. A compound of formula (I) according to claim 1, in which R₂ and R₃, which may be identical or different, are methyl, ethyl, methoxy, ethoxy or a group of formula (II), n is 1, 2,3 or 4 and, if n is 1, R₄ is C₁₂ -C₁₈ alkyl, cyclohexyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl or one of the groups of formulae (IIIa)-(IIId), in which R₅ is C₆ -C₁₈ alkyl, C₆ -C₂₄ alkyl interrupted by one or more oxygen atoms, cyclohexyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl, a group of formula (IV), aliphatic, cycloaliphatic or aromatic acyl containing not more than to 18 carbon atoms or an ##STR144## group where R₁₅ and R₁₆, which may be identical or different, are C₁ -C₁₈ alkyl, cyclohexyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl or a group of formula (IV) or ##STR145## is one of the groups of formulae (Va)-(Vc), in which X₂ is --CH₂ CH₂ -- or --CO-- or --COCO-- and q is zero or 1; R₆ is C₂ -C₁₁ alkylene; R₇ and R₈, which may be identical or different, are as defined above for R₁₅ and R₁₆ or hydrogen or R₇ is also (C₄ -C₁₈ alkoxy)carbonyl or aliphatic, cycloaliphatic or aromatic acyl containing not more than 18 carbon atoms, or ##STR146## is one of the groups of formulae (Va)-(Vc) or one of the groups of formulae (VIa)-(VIc), in which X₃ is --O-- or ##STR147## where R₂₀ is as defined above for R₁₅ and R₁₆ ; R₁₇ is as defined above for R₇ or R₁₇ X₃ -- is hydrogen, R₁₈ is hydrogen or methyl and R₁₉ is hydrogen or C₃ -C₂₄ alkyl; R₉ is C₃ -C₁₁ alkylene; R₁₀ is C₄ -C₁₈ alkyl, cyclohexyl which is unsubstituted or substituted with 1,2 or 3 C₁ -C₄ alkyl, benzyl, a group of formula (IV) or a group of formula (VII), X₁ is as defined above for X₃ or R₁₀ X₁ -- is one of the groups of formulae (Va)-(Vc) or (VIa)-(VIc); p is 1 or 2 and, if p is 1, R₁₁ is C₂ -C₁₇ alkylene and, if p is 2, R₁₁ is C₂ -C₁₆ alkanetriyl; R₁₂ is as defined above for R₁₅ and R₁₆ and R₁₃ is a direct bond or C₃ -C₂₄ alkylene; if n is 2, R₄ is C₂ -C₆ alkylene or C₄ -C₁₄ alkylene interrupted by an oxygen atom or by an ##STR148## group, where R₂₁ is as defined above for R₇ or R₄ is one of the groups of formulae (VIIIa)-(VIIIc) in which X₄ and X₅, which may be identical or different, are --O-- or ##STR149## where R₂₈ is as defined above for R₇ ; R₂₂ is C₂ -C₁₁ alkylene or a --C_(r) H_(2r) CO-- group, where r is an integer from 2 to 10 and the carbonyl group is bonded to X₄ or X₅, R₂₃ is C₂ -C₈ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, phenylene, phenylenedimethylene or a group of formula (IXa), in which R₂₉ is hydrogen or methyl or, if R₂₂ is C₂ -C₁₁ alkylene, R₂₃ is also carbonyl, or a ##STR150## group, where R₃₁ is C₂ -C₈ alkylene, C₅ -C₁₃ alkylidene, cyclohexylene or phenylene, R₃₂ and R₃₄ are C₂ -C₈ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene or a group of formula (IXa) and R₃₃ and R₃₅, which may be identical or different, are as defined above for R₁₅ and R₁₆ or the --R₂₃ --X₅ -- group is a ##STR151## group; R₂₄ is C₃ -C₁₁ alkylene; X₆ and X₇, which may be identical or different, are as defined above for X₄ and X₅, R₂₅ is C₂ -C₈ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene, methylenedicyclohexylene, carbonyl or a ##STR152## group, with R₃₁ and R₃₂ as defined above, or the group --X₆ --R₂₅ --X₇ is an ##STR153## group, where R₃₆ is as defined above for R₇, R₂₆ is C₃ -C₁₁ alkylene or a group of formula (X), where R₃₇ is C₂ -C₈ alkylene, C₄ -C₁₀ alkylene interrupted by 1,2 or 3 oxygen atoms, cyclohexylene, cyclohexylenedimethylene or methylenedicyclohexylene and R₂₇ is a direct bond or C₃ -C₂₄ alkylene; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe), in which R₃₈ is C₃ -C₈ alkanetriyl or aliphatic C₄ -C₇ triacyl; R₃₉ is C₂ -C₁₁ alkylene or, if R₃₈ is C₃ -C₈ alkanetriyl, R₃₉ is also a --C_(s) H_(2s) CO-- group, where s is an integer from 2 to 10 and the carbonyl group is bonded to the oxygen atom, R₄₀, R₄₁ and R₄₂, which may be identical or different, are C₃ -C₁₁ alkylene or R₄₀ is also a ##STR154## group, where the carbonyl group is bonded to the nitrogen atom and R₄₅ is C₂ -C₁₁ alkylene, R₄₃ is C₃ -C₆ alkylene and R₄₄ is C₂ -C₄ alkylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc) in which R₄₆ is C₄ -C₅ alkanetetrayl or aliphatic C₆ -C₈ tetraacyl, R₄₇ is C₂ -C₁₁ alkylene or, if R₄₆ is C₄ -C₅ alkanetetrayl, R₄₇ is also a --C_(s) H_(2s) CO-- group as defined above; R₄₈ is C₃ -C₆ alkylene and R₄₉ is as defined above for R₂₅.
 5. A compound of formula (I) according to claim 1, in which R₂ and R₃, which may be identical or different, are methyl, methoxy, ethoxy or a group of formula (H), n is 1,2,3 or 4 and, if n is 1, R₄ is C₁₂ -C₁₈ alkyl, cyclohexyl or one of the groups of formulae (IIIa)-(IIId) in which R₅ is C₈ -C₁₈ alkyl, C₁₀ -C₂₂ alkyl interrupted by 1 or 2 oxygen atoms, cyclohexyl, benzyl, a group of formula (IV), aliphatic C₈ -C₁₈ acyl or an ##STR155## group, where R₁₅ and R₁₆, which may be identical or different, are C₄ -C₁₈ alkyl, cyclohexyl, benzyl or a group of formula (IV), or ##STR156## is one of the groups of formulae (Va)-(Vc), in which X₂ is --CH₂ CH₂, --CO-- or --COCO-- and q is zero or 1; R₆ is C₂ -C₅ alkylene; R₇ and R₈, which may be identical or different, are as defined above for R₁₅ and R₁₆ or are hydrogen, or R₇ is also (C₈ -C₁₈ alkoxy)carbonyl or aliphatic C₈ -C₁₈ acyl or ##STR157## is one of the groups of formulae (Va)-(Vc) or one of the groups of formulae (VIa)-(VIc), in which X₃ is --O-- or ##STR158## where R₂₀ is as defined above for R₁₅ and R₁₆ ; R₁₇ is as defined above for R₇, R₁₈ is hydrogen and R₁₉ is C₈ -C₁₈ alkyl; R₉ is C₃ -C₅ alkylene; R₁₀ is C₈ -C₁₈ alkyl, cyclohexyl, benzyl, a group of formula (IV) or a group of formula (VII), X₁ is as described above for X₃ or R₁₀ X₁ -- is one of the groups of formulae (Va)-(Vc) or (VIa)-(VIc); p is 1 or 2 and, if p is 1, R₁₁ is C₂ -C₁₀ alkylene and, if p is 2, R₁₁ is C₂ -C₁₄ alkanetriyl; R₁₂ is as defined above for R₁₅ and R₁₆ and R₁₃ is a direct bond or C₃ -C₁₈ alkylene; if n is 2, R₄ is C₂ -C₄ alkylene, C₄ -C₁₄ alkylene interrupted by an oxygen atom or C₆ -C₁₀ alkylene interrupted by an ##STR159## group, where R₂₁ is as defined above for R₇, or R₄ is one of the groups of formulae (VIIIa)-(VIIIc), in which X₄ and X₅, which may be identical or different, are --O-- or ##STR160## where R₂₈ is as defined above for R₇ ; R₂₂ is C₂ -C₅ alkylene or a --C_(r) H_(2r) CO-- group, where r is an integer from 2 to 10 and the carbonyl group is bonded to X₄ or X₅, R₂₃ is C₂ -C₆ alkylene, C₆ -C₁₀ alkylene interrupted by 2 or 3 oxygen atoms, cyclohexylenedimethylene, methylenedicyclohexylene or a group of formula (IXa), in which R₂₉ is hydrogen or, if R₂₂ is C₂ -C₅ alkylene, R₂₃ is also carbonyl ##STR161## group where R₃₃ and R₃₅ are a group of formula (IV), or the --R₂₃ --X₅ group is a ##STR162## group; R₂₄ is C₃ -C₅ alkylene; X₆ and X₇ are as defined above for X₄ and X₅ ; R₂₅ is C₂ -C₆ alkylene, C₆ -C₁₀ alkylene interrupted by 2 or 3 oxygen atoms, cyclohexylenedimethylene, methylenedicyclohexylene or a ##STR163## group; R₂₆ is C₃ -C₅ alkylene or a group of formula (X), where R₃₇ is C₂ -C₁₀ alkylene, C₆ -C₁₀ alkylene interrupted by 2 or 3 oxygen atoms, cyclohexylenedimethylene or methylenedicyclohexylene and R₂₇ is a direct bond or C₃ -C₁₈ alkylene; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe), in which R₃₈ is C₃ -C₆ alkanetriyl or aliphatic C₅ -C₇ triacyl; R₃₉ is C₂ -C₅ alkylene or, if R₃₈ is C₃ -C₆ alkanetriyl, R₃₉ is also a --C_(s) H_(2s) CO-- group, where s is an integer from 2 to 10 and the carbonyl group is bonded to the oxygen atom; R₄₀, R₄₁ and R₄₂, which may be identical or different, are C₃ -C₅ alkylene, or R₄₀ is also a ##STR164## group, where the carbonyl group is bonded to the nitrogen atom and R₄₅ is C₂ -C₁₁ alkylene; R₄₃ is C₃ -C₅ alkylene and R₄₄ is C₂ -C₄ alkylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc), in which R₄₆ is a ##STR165## group, R₄₇ is C₂ -C₅ alkylene; R₄₈ is C₃ -C₅ alkylene and R₄₉ is as defined above for R₂₅.
 6. A compound of formula (I) according to claim 1, in which R₁ and R₁₄ are hydrogen or methyl, R₂ and R₃, which may be identical or different, are methyl or a group of formula (II), n is 1,2,3, or 4 and, if n is 1, R₄ is C₁₂ -C₁₈ alkyl or one of the groups of formulae (IIIa)-(IIId) in which R₅ is C₁₂ -C₁₈ alkyl, a group of formula (IV), aliphatic C₁₂ -C₁₈ acyl or an ##STR166## group, where R₁₅ and R₁₆, which may be identical or different, are C₄ -C₁₂ alkyl or a group of formula (IV), R₆ is ethylene or trimethylene, R₇ and R₈, which may be identical or different, are as defined above for R₁₅ or R₁₆ or hydrogen, or ##STR167## is a group of formula (Va), in which X₂ is --CH₂ CH₂ -- or --CO-- and q is zero or 1, or a group of formula (VIb) in which R₁₈ is hydrogen, R₉ is trimethylene, R₁₀ is a group of formula (IV), X₁ is --O-- or --NH--, p is 1 or 2 and, if p is 1, R₁₁ is C₂ -C₁₀ alkylene and, if p is 2, R₁₁ is C₂ -C₄ alkanetriyl, R₁₂ is C₁₂ -C₁₈ alkyl and R₁₃ is a direct bond; if n is 2, R₄ is a ##STR168## group; where R₂₁ is C₁₂ -C₁₈ alkyl, (C₁₂ -C₁₈ alkoxy)carbonyl or aliphatic C₁₂ -C₁₈ acyl, or R₄ is one of the groups of formulae (VIIIa)-(VIIIc), in which X₄ and X₅ are ##STR169## where R₂₈ s is a group of formula (IV), R₂₂ is trimethylene or a --CH₂ CH₂ CO-- group, with the carbonyl group bonded to X₄ or X₅, R₂₃ is --(CH₂)₂₋₆ --, R₂₄ is trimethylene, X₆ and X₇ are --O--, R₂₅ is ##STR170## R₂₆ is a group of formula (X), in which R₃₇ is --(CH₂)₂₋₆ -- and R₂₇ is a direct bond; if n is 3, R₄ is one of the groups of formulae (XIa)-(XIe), in which R₃₈ is a ##STR171## group, R₃₉ is trimethylene or a --CH₂ CH₂ CO-- group, with the carbonyl group bonded to the oxygen atom and R₄₀, R₄₁, R₄₂, R₄₃ and R₄₄ are trimethylene; if n is 4, R₄ is one of the groups of formulae (XIIa)-(XIIc), in which R₄₆ is a ##STR172## group, R₄₇ is C₂ -C₅ alkylene; R₄₈ is C₃ -C₅ alkylene and R₄₉ is as defined above for R₂₅. 